I've run the full studio on a Mac mini. The only part of the studio I couln't run was Motion 2 (needs a 64mb GFX card to install).
I've also run the Full studio including Motion on a new Powerbook without hitch.
Motion loves very powerful gfx cards, hence the reason I bought an X800 XT for my Powermac, I saw noticeable improvements over the stock 9600 that came with it.