Lost airs on ABC on Wednesdays at 9 p.m. EST.
Episode 2.16: The Whole Truth (Sun/Jin-Centric)
Airdate: March 22, 2006
• 03/03 - Sun wrestles with the thought of telling Jin a newfound secret that threatens to upset the entire balance of the survivors' community. Meanwhile, Locke enlists Ana Lucia to interrogate the prisoner in order to extract more information than he, Jack or Sayid could. Source: ABC
• 02/16 - Recurring characters Bernard, Rose, and Henry Gale will appear. Two guest starring characters will be Jae Lee played by Tony Lee and Dr. Je-Guy Kim played by Greg Joung Paik. Source: insiderscoop at the Lost ABC Forums
• 01/16 - [Yunjin Kim] said she's due in Hawaii immediately after the Globes to shoot her and TV husband Daniel Dae Kim's (Jin) next flashback episode - a romantic love triangle set to air in February. Source: USA Today

Episode 2.17: Lockdown (Locke-Centric)
Airdate: March 29, 2006
• 02/15 - During Locke's next flashback episode — slated to air in March or April — we're going to discover that he has a surprising connection to Sawyer. Source: Ask Ausiello @ TV Guide
• 02/10 - [This episode] will feature a kindly latino priest named Father Chuck. Don't know which characters-centric this will be, yet. Source: SecretAgentMan at TWoP

Episode 2.18: Title Unknown (Hurley-Centric)
Airdate: Spring 2006
• Note: It is not confirmed that this will be episode 2.18 but it looks likely.
• 03/01 - The episode will feature Phil, a mid-20s/early-30s affable man ΰ la Paul Rudd. Source: SpoilerFix.com
• 02/26 - [Jorge] Garcia says Lost fans eager to learn more about Hurley’s backstory will be treated to another Hurley flashback episode this season that depicts his time in a mental institution. "The episode is really interesting," he says. "[What happened to him while he was in the institution] was even a question I had." Source: The Trades

Episode 2.19: S.O.S.
Airdate: Spring 2006
• 02/26 - [This episode features] Isaac, a well regarded physical therapist who lives in Australia. Source: SecretAgentMan at TWoP

Episode 2.??: Title Unknown (Libby-Centric)
Airdate: Spring 2006 (Note that some source say the Libby episode may happen next season instead.)
• 01/25 - Q. Is it possible that Lost's Libby is not a doctor, but a ********** ****? Ausiello: That's what I'm hearing, yes. Source: Ask Ausiello @ TV Guide [Note: We do not know for sure what was *** out, but most LOST fans believe it's "compulsive liar" some think it's "television star." On February 1, Ausiello gave a hint: *******i** ****.]
• 01/24 - You will get your Libby episode. This season. Source: Matt Raggs at The Fuselage

General Season 2 spoilers:
• 02/27 - Things will get more complicated [between Claire and Charlie], from what I hear. Michael will soon reappear. Source: Kristin on E!Online
• 02/07 - The Easter Egg in "Fire + Water" that was on the sign on the building is Widmore Construction. We will learn more about them later. It is implied in the Podcast that the Alex with the Others is in fact Danielle's Alex. Source: Lost Podcast, February 7
• 01/30 - There is another undergroundy-ish thing that is hatch-like but not a hatch. And inside it, there is an important clue to the Others. Source: Kristin on E!Online
• 01/26 - Damon Lindelof reveals: And if you think Locke is dark, wait'll you see Charlie in a couple of weeks. Hell hath no fury than an addict scorned... Source: The Fuselage
• 01/25 - Co-creator/Executive producer Damon Lindelof reveals (note that this is a summary of the spoilerish things he revealed): The lines in the Dharma logo are not insignificant at ALL... but don't have anything to do with numbers. Perhaps if you were to break them down to their simplest elements, you'd find the significance. And more bunkers/symbols? Candle DID say there were more stations. And I'm not even sure the 'arrow' is an official station... looked more like a storage locker to me. If I had to guess, I'd think there'd be SEVERAL arrows scattered across the island, but they're probably just bunkers. [...] There are indeed other people on the island. But did Ethan KNOW Goodwin? Do they all live in the same place? How many of them are there? Source: The Official Lost Magazine, Issue 3, March/April 2006
• 01/25 - Writer/Supervising producer Javier Grillo-Marxuach reveals (note that this is a summary of the spoilerish things he revealed): Eko facing off against the 'monster' is a big deal in terms of the series because he's the only person - next to Locke - who has seen the 'monster' and has lived to tell the tale! Only with Eko, it was a different kind of encounter. That is something that the fans can expect to see bear fruit in future episodes. It's a hugely important thing, but won't necessarily be revealed immediately. [...] What you're going to see with Eko is that he has his own destiny on the island, and of all the characters, he has the most direct connection to the island because of the Nigerian drug plane. That's going to pay off in different ways. It's not going to mean necessarily that we wind up giving you the history of the 'monster' as a result of its interaction with Eko, but it sends Eko in a direction where he has a destiny to fulfil on the island that's gonna pay off. [...] You're going to begin to see a lot more of the Others, and see a lot more of what they're about and what they're doing. Source: The Official Lost Magazine, Issue 3, March/April 2006
• 01/23 - The Walt story will be resolved this season. In future flashbacks, we will get more answers about Jack's past. We will soon know why Hurley hasn't lost any weight. We will get more information about the hatch, what's behind the magnetic wall, what happens when we don't push the button. Source: January 23, Lost Podcast
• 01/17 - Dharma is an ancronym but not an anagram. Source: January 17, Lost Podcast
• 01/17 - Lost star Harold Perrineau (Michael) [...], as curious as Lost viewers about the fate of young actor Malcolm David Kelley (Michael' son, Walt), recently asked producers what's up. They told him, "Wait until Season 3." Source: USA Today
• 01/09 - There will be 24 hours of LOST in Season 2. Source: January 9, Lost Podcast [Note: This means one episode will have two hours. Surely the season finale.]
• 12/14 - "Ana-Lucia is straight," insists exec producer Carlton Cuse. Source: Ask Ausiello @ TV Guide
• 12/09 - Exec producer Carlton Cuse about the possibility of a Rose/Bernard flashback: "Given the road map for the rest of the season, we're not going to get to their flashback this year," he says. "But next season? Let's just say it's a very real possibility." Source: Ask Ausiello @ TV Guide
• 11/28 - The relationship between Locke and Eko will be a central focus of the show. The different viewpoint those two characters have will come into play. The Sayid/Ana Lucia relationship will be something that will carry foward in the upcoming episodes in ways that are different than people might think. They probably have more in common than "I killed the woman you loved." Desmond will be coming back. Maybe there will be an episode about the island's past. Source: Lost Podcast
• 11/28 - Writer/Supervising producer Javier Grillo-Marxuach reveals (note that this is a summary of the spoilerish things he revealed): You have not seen the last of Dharma, but it's going to be a little while before you find out a little bit more. The Dharma Initiative was a communal research facility on the island. A lot of scientists and free-thinkers got together to do a lot of different kinds of research: psychiatry, zoology - and remember that with the zoology of the film you saw some polar bears. It's possible there were some animal aggression studies going on there, as well as human psychology experiments and a whole variety of other things. The Dharma Initiative was founded by two peacenik Grad students who were trying to get to the bottom of a lot of mysteries about human behavior. There are six bunkers on the island, and they were devoted to a lot of different kinds of research. That's going to open up a lot of different avenues for us to tease you with what the kind of research was, and how it's evolved now that the Dharma Initiative seems to have fallen into disrepair. A lot has happened on the island and the Dharma Initiative is just the tip of the iceberg... The "funny" script pages posted online at OceanicFlight815.com sometimes get things wrong but sometimes they get them right... Will you be seeing "Zombie Walt" of "Clone Jack"? Probably not, but I think in everything that we do, there are hints of things that are happening. Source: The Official Lost Magazine, Issue 2, Jan/Feb 2006 [Note: At The Fuselage, Javi said that he misspoke "[The tailies] never saw or felt the wrath of the monster (and were never intended to!)."]
• 11/16 - Executive producers Damon Lindelof and Carlton Cuse reveal: It's always possible [Shannon] could pop up in someone's backstory. But she is definitely dead. When a character dies on the island, they stay dead. As we move into the middle run of episodes, we're definitely emphasizing the Jack-Kate-Sawyer romantic triangle. The level of sexual tension between those three characters is definitely being ramped up. As the respective leaders of their respective units, Ana-Lucia and Jack have a great deal in common with each other, and that's definitely something we're going to be exploring. But [the fact that] Ana-Lucia inadvertently murdered one of the members of the tribe doesn't exactly [lend itself] to candlelight dinners and walks on the beach. She is a woman; she will have romantic entanglements. But I think the one that will begin to emerge over the season will be the one that you least expect. I think that [the] question [as to what the numbers mean] will never, ever be answered. I couldn't possibly imagine [how we would answer that question]. We will see more ramifications of the numbers and more usage of the numbers, but it boggles my mind when people ask me, "What do the numbers mean?" You'll learn more about [why Ethan abducted Claire] this season. [We still plan on revealing why the plane crashed this season.] [We will learn more about the monster this season.] Source: Ask Ausiello @ TV Guide
• 11/11 - Maggie Grace is not expected to return to Lost island in the future. [There are no other deaths in the works.] Source: Kristin on E!Online
• 10/24 - Desmond will be back. Source: Kristin on E!Online
• 10/11 - Says Lindelof: "I think the audience is very compelled to figure out exactly where Desmond was running to and, once he gets there, what is he going to do. We told you that he was in a [ship] wreck, but I think there are a lot of questions about how exactly he came to be here. That's certainly a story on the horizon." "It's important to note," Lindelof says, "that we've never said when the plane crashed. I think the assumption is that it happened in 2004 when the show premiered, but we've never said that." "The Helen we meet in flashbacks is not the same Helen that Locke was speaking to on the phone," Lindelof clarifies, sort of. Source: TV Guide
• 09/26 - Lindelof reveals: [Season 2 will cover] roughly the next 45 or 50 days. We’re sticking to the same brand of storytelling and not taking bold jumps forward. Probably by the end of season two we’ll be in the range of day 90. The issue of what made Flight 815 crash is going to be dealt with in season two and definitively answered by the end of season two. Source: SBC
• 09/19 - From Damon Lindelof: [Hurley getting a love interest is] definitely something we've thought a lot about and nothing that we wanna force. We're doing 23 [episodes] this year. There is going to be a flashback story that fully explains the significance of all [Jack's] tattoos and puts it into the framework of what was happening in his life when he got them. You'll probably be seeing it in season two, but if not, very early in season three. Right now the plan is to do it this year. [23] is an important number in terms of the scheme of the show. Source: Kristin on E!Online
• 09/01 - Series co-creator David Lindelof said Vincent "will play a big part" in the series' second season. Source: Pittsburg Live
• 08/10 - From writer Javier Grillo-Marxuach: Danielle has been on the island 16 years, despite the fact that the translated French message is inconsistent on the "iterations". Source: The Fuselage
• 07/25 - The crash of the plane is explained before the season ends. Source: Statements at TCA
• 06/14/2005 - Quotes from Lindelof and Grillo-Marxuach at a Lost convention: The plane did not crash by accident, it crashed for a very specific reason. But he dismissed speculation that someone aboard the plane caused the crash. Source: The LA Times

this information is taken from
Lost Spoilers