upc, I believe the NetBurst architecture is a dead end. I don't know about bulk wafers used for a Dothan design. Until we see AMD's 90nm SOI matched head-to-head against Intel's 90nm bulk then we really won't know the answer.
AMD's 90nm product is about to hit the street. Give it 3 months to come up to speed, then compare the thermal and power characteristics between the A64 mobile and Dothan product lines (being sure to normalize for the differing definitions AMD and Intel use for this). Then you will have your answer.