The PC from Tigerdirect is actually a decent build but not for your application. A six core processor will actually make your WoW playing experience worse than a 3 or 4 core rig. Also that system has no discrete graphics card which you would need to play WoW. Below is a link to a well balanced system off newegg for $475 before rebates.http://secure.newegg.com/WishList/PublicWishDetail.aspx?WishListNumber=21929828
The processor/mobo combo is a great deal that batuchka recommends from microcenter. I'd get that instead of the mobo/processor in my build if you can get to a microcenter. My motherboard and processor come to $160 and the microcenter $150 combo is a real steal. Its a better processor and better brand motherboard.