Various articles recently have provided new details on the new movie, and the prequel comic series Countdown. Firstly (though actually most recently) an interview with Robert Orci at TrekMovie.com reveals how the new movie will take place in an alternate timeline which diverges from the point Nero travels back in time, so the USS Kelvin is part of the original/main Trek timeline, while the new Enterprise and Kirk's different career path exist in the newly diverged timeline.
I think Christopher L. Bennett's summary of this news at the TrekBBS describes it best: "So basically this is a Myriad Universes movie, so to speak. It's a tale about an alternate Trek universe that exists alongside the "classic" one. And yet, like some of the MyrU tales, it provides some insights that can be presumed valid where the main timeline is concerned."
See the original TrekMovie article for much more in depth discussion about all the quantum theory and such that makes this idea work. I'm quite curious to see if this will actually be explained within the film.
Meanwhile, back in the original timeline Countdown will be showing us the lead-up to the film in the 24th century, and the creators have been talking about that. In an article at Comic Book Resources the writers, Mike Johnson and Tim Jones, have described the series as "a very poignant character piece tracing the steps of Nero, who descends from a proud Romulan patriot to a murderous arch villain". Another TrekMovie interview with Robert Orci confirmed the series takes place after Nemesis (still no details on Data's role) and IDW's new Trek editor Andy Schmidt also commented on the series in an interview at Newsarama "You'll get a lot of firsts in this series - you'll see a lot of stuff that's in the movie for the first time here and get to know the characters so that when you walk into the film, you're already going to care about them. They're really tremendous characters with a lot of dramatic conflict and flair."
In that same article Schmidt teased at new things in the works from IDW, commenting that Trek comics will take a "bold direction change, but I will say it is not entirely because of what the film ‘does’ to the series. But things are only beginning to heat up!"