Peter Jackson has been talking to Moviefone regarding the Hobbit and has addressed a number of issues including delays (or lack of them really)
“Well, it's not really been delayed, because we've never announced the date. I mean it's sort of interesting because the studio [MGM] has never greenlit 'The Hobbit,' so therefore 'The Hobbit' has never been officially announced as a "go" project, nor have we ever announced a date. But there's so much interest that people -- newspapers and magazines, of their own account, say, ah, it's likely to film in May, it's likely to film in June, it's likely to film in September. People make this stuff up. And then if it's not filming in June, you get a story saying, "'The Hobbit's' been delayed." But it's never actually been announced.”
He also addressed when they MIGHT start shooting and some bits about the script
”We've just delivered the script. Literally last week, we delivered the second of the two screenplays -- the first draft. So the studio's got both scripts now, which is a milestone; and if anything was holding it up, it was us doing the screenplays, because we'd just been writing as fast as we can, but it took us this long to get them finished. So we take whatever responsibility there is for the speed. And we're now in the process of budgeting the films, and then hopefully we'll get to a budget the studio [people] are happy with, and they'll greenlight the movies and we'll announce the shooting dates. I'd be pretty optimistic that we'll be shooting before the end of the year. I would imagine October, November, we'd be shooting by. I'm not announcing it, though”
And on the casting of Bilbo Baggins
”No, there's no definite ... I mean, any character that's returning from 'The Lord of the Rings,' we obviously would love the same actors to play. But even those actors haven't been approached yet, or there [haven't] been any deals done. And the studio wouldn't organically do any of that until they've greenlit the film.”
So interesting times ahead for The Hobbit. Baring in mind that it’s going to be in 2 parts I’d imagine end of 2012 or 2013 for part one, if what Peter says comes to fruition.