Deadline has confirmed that action star Vin Diesel is in talks with Marvel to provide the voice for Groot, the sentient, talking tree in James Gunn's forthcoming film Guardians of the Galaxy.
Whether the story would remain true to the character's comic book persona is difficult to say; it would seem a waste to use a big name like Diesel to do voice-only work for a character who says only one thing ("I am Groot!").
Earlier today, Diesel posted an image of Groot from the comics to his timeline on Facebook; it was removed shortly thereafter, something that's likely to keep rumors alive right up until the official announcement comes along of Groot's casting. That's not all, though; Deadline claims to have been told by their own reliable sources that it's the Groot role that Diesel has been in the running for.