Can't be sure, we have to wait and see, i think they were meant to be 10% or something like that faster than sandy bridge or something (i wouldn't assume anything, the next gen could either be how it should be or it could be bulldozer 2.0)
Well Intel's Haswell will come out next year April apparently and Piledriver comes out either next month or in one of the next months after next month...
Piledriver CPU's were estimated to be 15% faster than Zambezi CPU's and also use less power.
I hope the update is going to be as big as the update from Phenom I to Phenom II.
I think PD will be significantly better.
I recently bought a lappy with 4500m trinity APU and thats based on PD and they are a big improvement over the old APUs and im not talking about the GPU part.
The CPU part of the APU is about 15% faster than the previous gen.So I would say if you were to get the PD you would get performance equivalent to the sandbridge i7s.
Thats still not as fast as Ivy but it will still be a better price/performance deal.