I'm in the market to purchase a new Mac with the intent of pushing what Motion and After Effects can do (3D and Particle Emitters in HD). With this in mind and the new MacBook Pros that just came out, what would be my best bet if I didn't want to spend more than $4k on the base unit? I can always add more Hard Drives and Ram at a later date. I do like being able to have a portable studio, but there is always the trade off on multithreading/cpu power (is Motion coded to take advantage of a multi core system?). I know there will be more information that you'll want to know to help sway a decision, but it's late for me and I'm feeling a little foggy.
Forget the Macintosh portables. they will never be the powerhouses you need to "push" any application. convenient and cool, maybe, but one buys a portable because it's portable, not because Apple hypes it as appropriate for video editing.
Drives aren't the issue, neither is RAM. You must be able to expand or replace the graphics card because whatever they're putting into them today will be obsolete in a few weeks. Adobe's promise of OpenGL is a cruel joke and the next rev of Final Cut Studio might be heavily dependent on the GPU much like Motion is today.
This is my standard sigfile so do not take it personally: "For crying out loud, read the freakin' manual."