Plus all current cpu's had two threads per core so they've already figured out how to develop . It's just adding extra cores and threads per core. Cell is a different cpu altogether and isn't even close to pc standards. It has 1 core +spe's.
The gen cpus and pc gaming will only increase in cores and 4 threads is just an evolution of a perfected technology which was 2 hardware threads per core currently.
The main difference is that there are more cores and extra threads. When have any of you ever said that a dual core with two threads per core was better than quad core with two threads