It wouldn't surprise me if he had one of each mac though and rotated through them though.
He probably also uses some of the prototypes of the next generation computers to make sure they meet his standards.
I bet he also has PC, what do you guys think?
I remember a series of black and white photos taken of Jobs at his house three of four years back. Of course, I can't find these now. A couple were taken in his study and showed a large Apple monitor, which would suggest a Pro or a Mini. I somehow doubt he'd settle for a Mini though.