I'm looking for a rig that will last me through four years of university (I'm moving away so taking my desktop wouldn't be as easy as a laptop). I want it to be completyely decked out with all the frills. So... can a laptop have both dual CPU and GPU?
You can have a dual core CPU (which is like 2 CPU's) and Dual graphics cards, yes.
Honestly, with the 7900 GTX you simply don't need 2 GPU's with notebook resolution. I offer an SLi (dual GPU) machine, but I don't recommend it. The mobile 7900 GTX is clocked higher than the desktop 7900 GTX.