An unconfirmed internet rumour has surfaced tonight that suggests that David Tennant may provide the voice for Rocket Raccoon in the forthcoming film adaptation of Marvel Comics' Guardians Of The Galaxy. The rumour was first posted by the Marvel Cinematic Universe Facebook fanpage who claim that they were given the information exclusively. Marvel themselves have given no indication that there is any truth to this.
The film adaptation will be based on the second Guardians team from the 2008 reboot of the original 1969 series. Directed by James Gunn, it will be produced by Marvel Studios and distributed by Walt Disney Motion Pictures. Confirmed cast so far include Chris Pratt, Dave Bautista, Zoe Saldana and Lee Pace. The character of Rocket Raccoon will be a combination of GCI and motion capture.
The film is due to be released on 1st August 2014.
Source: Marvel Cinematic Universe
EDIT 8th May 2013:
Bleeding Cool have since reported that Marvel have denied David's involvement.