You're not understanding it right. Vista Home Basic and Home Premium will support and utilize an unlimited number of "cores". They just won't support separate physical processors; you need Business, Ultimate or a Server edition for that. Most computers you buy have multiple "cores", not multiple physical processors.
But now I see that you've already figured that out. Actually Business and Ultimate only support 2 physical procs. You have to buy a Server OS to get support for more. But like I said, most people have multiple cores, not processors.