What is your prediction for the AMD Bulldozer?
I think the lowest speed Bulldozer FX-4100 model will at minimum be 10% faster than a i7-2600k and the FX-8170 will be 60% faster than the 2600k and could be as much as 100% faster. With the lack of news coming from AMD, I expect the speeds to blow the socks of most everyone. Generally quite before the storm.
Ultimately I think we'll find out on September 19th for sure. For gaming, the bulldozers won't be anything special. Very few games will use more than 4 cores. I've seen some information on the clock speeds, but remember that 6 core Phenom IIs don't beat similarly clocked 4 core i5s. The bulldozer is an entirely new architecture, so it's hard to say what kind of performance you're looking at with 3.8ghz. Wait for the benchmarks in the third week of September and remember that Ivy Bridge will outperform Sandy Bridge by at least 30% just because of the 3D transistors and those same transistors might make it efficient enough to have desktop models with 8 cores.