Next Year's Mac Purchase?

I am looking to purchase a new Mac sometime next year. I'm a graphic designer. I work with with Adobe CS2, Flash 8 mostly. I plan to do some light 3D, Video and possibly Audio Editing in the near future. At the moment I use an iMac 17"FP(G4/800mHz) and it does a descent job. My question is if I should go with a Laptop or another iMac. Years ago, there was no question that anything less than a tower wouldn't cut it but now with Laptops being so powerful, I'm rethinking if I should just go with a Laptop. Anybody of any options or idea's about which way to go? Thanks for any input.

~e