Spoilers are flying around, so here is a thread to keep them all on to stop people who do not wish to know reading them.
On May 7th 2007, it was confirmed that Season 4 will return in February 08 for a 16 episode run, followed by another 2 16 episode seasons in 2009 and 2010 [1].
The band of friends, enemies and strangers continue to work together to stay alive. But as they have discovered during their 70-plus days on the island, danger and mystery loom behind every corner, and those they thought could be trusted may turn against them. Even heroes have secrets.
For the third consecutive season, “Lost” ranks No. 1 in its time period in Adults 18-49. It is Wednesday’s highest-rated scripted TV program in Adults 18-49, and since entering the hour also qualifies as the No. 1 10:00 p.m. series on any network.
“Lost” stars Naveen Andrews as Sayid, Henry Ian Cusick as Desmond, Emilie de Ravin as Claire, Michael Emerson as Ben, Matthew Fox as Jack, Jorge Garcia as Hurley, Josh Holloway as Sawyer, Daniel Dae Kim as Jin, Yunjin Kim as Sun, Evangeline Lilly as Kate, Elizabeth Mitchell as Juliet, Dominic Monaghan as Charlie and Terry O’Quinn as Locke.
“Lost” was created by Jeffrey Lieber and J.J. Abrams & Damon Lindelof. Abrams, Lindelof, Bryan Burk, Jack Bender, Jeff Pinkner and Carlton Cuse serve as executive producers. It’s filmed entirely on location in Hawaii and premiered on September 22, 2004, is from ABC Television Studio.
Retrieved from
http://www.lostpedia.com/wiki/Season_4Occurences on the IslandTime
3-30-07 Lost Official Podcast
The survivors will celebrate Christmas on the island sometime in Season 4.
Location
5-02-07 Preston & Steve Morning Show via The Tailsection
Damon Lindelof and Carlton Cuse: The four-toed statue is very important but won't be addressed until season 4.
5-02-07 DarkUFO
Depending on how things go with ABC there is a rumor the big set for season four will be the `ruins'.
Returning characters
Jacob
EW.com Damon and Carlton Q&A 5/8
Jacob is a character who is every bit as significant to our universe as the Emperor was to the Star Wars universe. Jacob is a guy who is going to have a very significant, ongoing sort of story value in our show.
Mrs. Hawking
EW.com Damon and Carlton Q&A 5/8
Lindelof: You will be seeing her again.
Juliet
Watch with Kristin 5/7/07
Dr. Juliet Burke is sticking around for the foreseeable future
Walt and Michael
Official Lost Podcast/March 5, 2007
We will see more of Michael and Walt [but not necessarily in the third season]
Kristin on E!Online[1]
Carlton Cuse: We will only go back to Walt and Michael once we have the sufficient knowledge to comprehend what the writers want to show
us.
Cuse: There's a circularity to the way that story is going to unfold in the overall mythology, and that is a long, planned approach. Yes, we'll get back to the Michael and Walt story, and it will be really compelling when we do. But that's most likely a year 4 story.
3-01-07: From Kristin on E!Online[2]
Harold Perrineau is trying to figure out if he can get back next season and do other work as well
Rousseau
2-20-07: From "fficial Lost Podcast" href="http://www.lostpedia.com/wiki/Portalfficial_Lost_Podcast">Portalfficial Lost Podcast"
Damon and Carlton denied a Danielle Rousseau flashback episode until year four.
5-3-06: From Ask Ausiello[3]
"The story of the wrecked research vessel, it will be coming at some point."
4-23-07: Lost Podcasts
There will be a Rousseau flashback eventually. In it, it will talk about Montand and his arm.
Libby
11/15/06: Ask Ausiello
Lindelof: "We would love to tell the rest of Libby's story, it’s just a question of whether we get to it. I think we're going to try to tell the stories of our regular characters before we do that." Damon: "Obviously, we have a couple more beats of Libby’s story to tell to fill in the missing pieces, and the way we would tell that story is in the flashbacks of another character. But that character can’t be a character that we already know and love, otherwise they would recognize Libby. We know who those characters are and what those story beats are, but it might be a while before we get to their flashbacks."
Kristin on E!Online[4]
Cuse: Given everything else we have to tell, Libby’s story is going to be a mystery that's going to have to get answered in year 4. Lindelof: There's really one significant missing piece to Libby's story. How did she get from A to B — from Desmond to the mental institution? We know the answer to that question, but the only way to tell that story is through another character's flashback, and that character would have to be another character on the show who is not among the beach dwellers.
Non-returning characters
Charlie
3-01-07: From Kristin on E!Online[5]
Life & Style magazine is reporting that Dominic Monaghan (Charlie) has been told he won't be back for next season.
Paulo and Nikki
4/11/07: Ask Ausiello
Carlton Cuse: "Paulo and Nikki are definitely dead. Until the zombie season. And neither Paulo nor Boone were gay."
Retrieved from
http://www.lostpedia.com/wiki/Season_4/spoilers