Keyclone definately runs either: several copies of WoW on one machine, 1 copy of WoW on each machine over as many machines as you like. I currently use it to run 1 on my main PC and 4 more over 2 PCs (1/2/2) with great ease.

Highly recommended for the small price to buy the software. The creator is also very active on the forums and is happy to help with any bugs you discover etc