I have to agree with the OP that CPU's are slowing down in progress, but (A) its not the engineers being lazy and (B) CPU performance can come a long way with proper software.
I think the biggest limitation today with CPU progress is physical. Why did Intel abandon a 4GHz P4? They were approaching the physical limits of the mfr process they were using; heat and size were increasing TOO much to be feasible as a long term plan. There is a LOT of research going on today as to how to improve transistor manufacturing, but IMO they are all just trying to find a way to extend the life of good ol' silicon. Realistically we're approaching the limits of silicon in its current incarnation, now matter if you use low-K, SOI, 90nm, 65nm, etc. Problems like leakage current due to shrinking gate/junction sizes, low yields due to complex processes, etc are all pointing to the fact that we are pushing silicon's limits. I think before we see a revolutionary change in CPU's, we'll need to see a revolutionary change in device fabrication.
On the other hand, we could see huge CPU advances with a change in logic. Kind of like Intel abandoning the MHz game, what if a completely new architecture made computing a LOT more efficient using current tech? Of course this also brings into consideration the software side of things, as you have to have an OS & programs to take advantage of this highly efficient architecture. I find the possibility of a logic revolution less likely than that of a fabrication revolution, mainly because (A) people are used to thinking in a certain way (i.e. x86) and (B) it would involve a massive change that would be damn near impossible to do unless it was led by someone like Intel. Sure, Cell has some promise and in future incarnations...who knows. I haven't read up enough on it to intelligently comment, but I think it is a step in the right direction.