between the NVIDIA 8800GS GPU that's on the 24in iMac and the NVIDIA 9400 (or is it 9600) that will most likely be placed on the upcoming release? Is there a big difference between the two? I'm not into heavy video editing, but will soon be using FCE and iMovie when I get my new video cam in a few months. No major video editing but I would like to mess around with it. Will there be a major difference?