WoW is NOT CPU limited. It is GPU limited. It also has very light video requirements, especially if the game is minimized or fairly small in settings (resolution does have an impact but less than one might expect). With a few gigs of ram and depending on how much FPS loss you are willing to accept, it is possible to run 5 on a single dual core system with a decent video card in what most would consider a "playable" state. I have not researched this in depth because, well, I have separate machines but as hardware gets cheaper and cheaper, I don't see why you could not run 5 WoWs on a single computer without much difficulty and the right software. You are still going to have a few limitations of course but nothing too bad and most of which (but not all) can be worked around or minimized. But I will leave that to others to fully explore and report on.