Hawk, I have a quad core (Phenom II 940) and I agree with Yarlen that it helps because the computer has background programs/services running and one core can focus on the game. Now, on that front, having a high Ghz dual core is probably ideal for this game since quad cores generally have slower clock rates, but I don't buy a new processor just to optimize one game.
Now, when Bulldozer and Ivy Bridge come out, I'll probably upgrade my computer just because I can, but I'm certain at that point I could probably run 5 games of SoaSE at once.
