Doug, while I subscribe to the thesis that Intel will be pressured to lower Xeon prices, AMD has to increase K8 manufacturing before that effect kicks in. Don't look for it in Q4 results, you will not find it. Maybe in Q1, definitely by Q2, IMHO.
Remember, server sales are long lead time qualifications for a new design. Opteron has been out in the wild since April, so the demand for it should be kicking in pretty soon. We saw the start of that in Q4, but that was just the first few raindrops of the storm.
Brace yourself...