I don't know if you've heard the latest rumor / conspiracy theory about Guardians of the Galaxy, but some people are suggesting that Vin Diesel won't actually be voicing Groot in the space adventure, but has instead been signed up to play Thanos.
But while it sounds plausible to me, it looks like there's no truth to the rumor, as [Guardians of the Galaxy](movie:424073) helmer, James Gunn, was quick to point out during a Facebook Q & A:
So who do we believe?
I think there could be some traction to the rumor. Vin is a huge action star, so it seems a waste to only use him as the voice of a talking tree who only ever says "I am Groot". And just because Gunn has come out and told us there's nothing to the story, that doesn't mean he's actually telling the truth. It wouldn't be the first time Marvel has pulled the rug from under us **cough The Mandarin Cough**.
What do you guys think? Is Vin voicing Groot or the Mad Titan?