Zach, the problems not the CPU, in fasct most systems single processor 1.5 ghz processors would handle your high graphics with 1000 players no problem. the problem comes from the system bus, graphics cards, memory and hard drive access times.
the current configuration of the workings of a PC preclude and and limit the full potential of Multi-core CPU's. In order to make games super fast, most pages of he drawn Game would have to reside in memory, be updated very fast from th hardfdrive to the graphics card to main memory, every time something has to move, it slows the system down. not only that, but the faster we make hings go, th more heat the system produces, which is another problem they are trying to address, as we know heat is the arch-nemisis of micro-electronics.
upping the bus capacity and HD access speeds are a solution, however, they have hit a roadblock on both of those HD access speed can only spin plates at a max speed before bad things start to happen, so Like i said, we'll have to wait 10-20 yeas for the actual workings of a PC to progress to the point it can handle great graphics on an MMO scale.
IBM has made some progress on these issues, but the costs are astronomical right ow, Nano-technolgical CPU, that run 165% cooler (IIRC), Optically accessed HD'sMulti-bus actitectures, and there's even some speculation of high Ram video cards that can take 100% memory control, such that they don't have to read/write to main memory to speed things up. Unfortunatly, OS's and motherboards have not progressed well to use all this technology yet.
