I think I can understand where the OP is coming from. On the mainstream side, we've barely just gotten out the door with dual cores, and already we have quad core CPUs that have already made dual cores obsolete. There's projection that 8 core, 16 core, and higher are in the not so distant future as well.
It's sad but that's the way technology goes. Since there seems to a be a wall in terms of the frequencies that CPUs can reliably hit, the amount of cores is what AMD and Intel are going for now. It will only increase exponentially until another wall is hit. Then who knows?
The good thing, though, is that Intel is leading the way in an attempt to make quad cores affordable (besides trying to crush AMD) with their frequent price cuts. So when it's time for you to build a new setup, you'll very likely be able to put a new multi core setup fairly cheaply in relation to the cutting edge technology that you're buying.