I knew there would be some interesting answers to the question.
And here they are... (Taken from Twitter responses and comments here.)
The dude from the I'm A Mac commercials. (Justin Long.)
A young James Stewart
Ben Kingsley. (Dressed as Gandhi.)
CNN already asked the question. (Darn!)
Charlie Sheen. (My own first choice.)
Jack Nicholson. (You can't handle the truth.)
Alec Baldwin. (In his Jack Donaghy role.)
Samuel Jackson. (John Travolta?)
Boris Karloff (Is it a vampire movie?)
Seth Rogen (as Woz).
Keanu Reeves. (Laurence Fishburne as Woz? Agent Smith as Bill Gates? The Oracle as Jony Ive?)
Patrick Stewart. (With Data as Woz?)
Fake Steve Jobs. (Good one!)
It should be animated, by Pixar. (Good one!)
Bill Gates. (?)
Ralph Fiennes in full-on sociopath mode.
The guy who plays Hitler in all the Youtube videos.
Robert Downey Jr
Jason Statham. (Assuming it's a heist picture.)
Humphrey Bogart in the Cain Mutiny.