I run far older gear than that and have no troubles running 5 copies of WoW.

My current machine has got (From memory)
*XFX 680i motherboard
*8800GTX x2
*E6850 CPU
*4gig of corsair standard ram
*Plain old 300gig HDD (Though I do have two raptors in there but for other things)

In other words, you amchine is going to blitz it.


I should note that I don't run WoW at full settings, though my main client generally runs on high or Ultra (minus shadows) so you should be fine.