It's confirmed that T.J. Miller will be playing Weasel in the Deadpool movie.
Miller posted a series of tweets confirming the character.
Weasel, in the Marvel Comics, supplies Deadpool with weapons, tech and intel and was actually a classmate of Peter Parker's.
"Deadpool" has a February 12, 2016 release directed by Tim Miller starring Ryan Reynolds and Morena Baccarin.
Watch the Deadpool test footage: