Essentially I'll probably end up using both PCs for much the same thing as I quite often run games on both PCs at the same time, and would probably have iTunes and web browser on the utility PC also. I know that in some ways the quad core might be better suited as the utility PC as it will be better at running multiple apps but it's hard to fight against a lifetime's habit of having my more expensive PC as my gaming machine!
I've got a couple of questions...
I'll end up with 8gig of Corsair XMS2 DDR2 6400 (800) and 4gig of Dominator DDR2 8500 (1066) memory. I'm intending to stick the 8gig of slower memory in the utility PC to help with having several apps open at once, and the 4gig of faster RAM in the quad core, since it should be more than enough to deal with most games.
I've currently got Vista 64 Ultimate on the E6850 and have picked up a copy of Vista 64 Premium for the quad core. Is there any reason I should consider running ultimate on the quad core? I never use the features like Aero etc. Is there anything in the build of Ultimate that makes it better suited to my newer PC?