This may be nothing, just another random Internet rumor based on not much. Or it may be the first inkling of how Peter Jackson et al. are planning to change the ending of The Hobbit to make it more cinematic. Please notice the emphasis on the word "may," as there is a lot of conjecture here.
What's got us so interested is a story on the (very reliable) TheOneRing.Net about some casting information they came across.
...if things go well with MGM and Spyglass in the next few weeks, 'The Hobbit' will head to production in January, pending negotiations with [Martin] Freeman and filming could tie up actors for a year. (January happens to be an excellent weather month to shoot at the Hobbiton set.)
And, inadvertently, we know of a possible change to the plot. The character summary says:
although . . . he doesn't have huge courage he does become, particularly in the last battle, very brave.
As readers will remember, Bilbo is mostly knocked out for "the last battle" which we can assume is The Battle of Five Armies. (That title would mean very little to some actors.) No filmmaker, definitely including producer and probable director Peter Jackson could resist filming and showing such a battle with all its action and emotional wallop, despite the titular character from the source glossing over it (and that is obvious with no spy information at all). But this information is a possible plot reveal that Bilbo will remain conscious and the 'film Bilbo' will get to see wonders of battle that 'book Bilbo' never did and perhaps play a brave role.
This sounds like it could be true to us because is it's exactly the kind of change we'd expect to see Jackson make as he translates the pages of The Hobbit into film. (Another reason is that a lot of solid information has come out of production and casting documents over the years.)
He made quite a few adjustments to The Lord of the Rings story as well, and most of those made similar sense and turned out well. So although this is pretty thin (one line in a casting document that may or may not even be real), we think it's worth taking note of and remembering as The Hobbit continues to movie forward, if you're the kind of person interested in such things.
For the record, if all the above is true, we're perfectly fine with this potential revision to the end of The Hobbit for exactly the reasons TheOneRing.Net outlines.