You may have read in The Sun yesterday that Tobey Maguire had bagged the role of Bilbo Baggins is The Hobbit. As it came from The Sun, I'm sure you viewed it with suitable scepticism, and you were right to.
Although Maguire was rumoured for the role a while back, he himself debunked it at the time. However with him now leaving Spider-man 4, that could have changed.. except it hasn't. AICN took the trouble of e-mail Peter Jackson and Guilermo Del Toro about the new speculation that Tobey would be their Bilbo.
Jackson replied, "No truth at all, although we're all big fans of Toby [sic]. We are currently auditioning for Bilbo, and a month or two away from any announcements."
Del Toro merely said, "It's not true."
So that would seem to be that... until of course they turn round and announce Maguire for the role (although I'd call that a long shot).