This is my cast for a Deadpool movie
Deadpool: Dane Cook
Funny and animated just like DP. There are certainly other actors (Ryan Reynolds, Seann William Scott) who could play DP but i think he's best choice
T-Ray: Andrew Bryniarski
The guy is big, mean, and intimidating. He was Leatherface in TMC remake and Lobo in the short Lobo's Paramilitary Christmas Special
Weasel: Paul Costanzo
He usually plays the smart but witty guy (see: Road Trip, 40 days and 40 Nights). He also has the scrawny look of Weasel
Blind Al: Phyllis Diller (up to debate)
Blind Al's sense of humor is on par with DPs except theres more sanity to it. Who better then probably the most famous female comic who is very quirky
Deadpool stunt double: Tony Ja aka Ong-Bak
The guy is the next generation Bruce Lee. He's starting to gain some recognition with Ong-Bak so he might not want to be a stunt double although he could become a very successful stunt man (ie seeing movies hes a stunt man in just because he is in them)
Tolliver: Jack Palance
The guy is cool and collected while still having the Clint Eastwood voice and demeanor. Plus he looks just like Tolliver.
Taskmaster (voice): Hugo Weaving (Smith from Matrix, voice of V of V for Vendetta)
Hugo's voice was very good in V for Vendetta although the upbeat tone didn'tfit i thought, but the way he protrayed Smith in the Matrix movies might work behind the skull mask.
The Director of Weapon X (renamed The Program to save confusion with X-Men): James Cromwell
I just think Cromwell is a good actor and I've seen many different versions of the Director from the Weapon X program and he seemed to fit the profile especially after his role in LA Confidential.