I have a model called the Executioner
that has a 7900 GTX 512 MB, up to WUXGA resolution.
I am receving a T7400 Core 2 Duo 2.16 Ghz this week and testing it in this system. Why wait until Q4 until they are released in the U.S. or take that chance that your notebook can't upgrade?
If you are doing a lot of encoding and disk intensive processes, you may want to go with two 7,200 rpm hard drives in a a RAID0 configuration, or a 64 GB FLASH RAM hard drive for your OS, programs and renders, and a second 7,200 rpm hard drive for data, media and larger rendering. There is where your bottleneck is going to be.
The memory is a good idea, but the price of the 2 GB chips are somewhat impracticle for the average Joe right now. http://www.killernotebooks.com/images/logos/insignia_small.jpg