Agreed. I've said it before and I'll say it again: significant performance increases in the x86 world are a thing of the past.
There simply isn't enough money in the market chasing higher performance to make the development cost of faster chips worth the investment.
This is actually an opportunity for AMD. I expect it costs AMD less to catch up to Intel than it costs Intel to push to faster speeds, and since Intel isn't being paid anymore to get faster, AMD can, like the slow and steady tortoise, gradually catch up to Intel. I believe it will take a couple more years, but if AMD survives that long, I believe that it will have achieved near performance parity with Intel by then.
And then neither company's offerings will get much faster, forever thereafter, until there is some new kind of 'killer app' that demands increased CPU speeds that people are willing to pay for (could happen anytime; but the way things are going, with everyone moving to mobile phones and pads, I think we're in for a relatively long haul of form factor and power usage dominating the marketable characteristics of CPUs).
I believe Intel will continue to hold a power advantage over AMD for a long time though, but AMD will gradually narrow that gap as well.
The thing is, AMD will be fighting Intel for a stagnating/shrinking CPU market, and more than likely AMD won't increase its margins significantly during this process, it will just reduce Intel's margins. Not really good news for either company, but worse for Intel.