It seems funny how people can be lead to believe almost anything they here. I don't wish to scrutinize, only set some things straight (I'm sure a bunch of people are going to say "in your opinion...").
Anyways, back in the day of the K6 processor, Intel lead the market for reliability purposes. Athlon struct back with the Duron. They had increased reliability and profit, but not enough to keep up with Intel.
Amd decided the way to get ahead is to simply "rethink their inks." Their engineers developed a processor that had a more efficient design. This allowed for executing most 32-bit instructions in less CLK cycles.
This simply put is how AMD is staying ahead in effieciency category. They do not lead in marketing or heat efficiency.
My only thought, that has no merit and is purely opinion, is that the reason they are so hot is because of the short pipelines; providing faster speeds but less area for "natural" cooling.
Oh yeah, and that bus speed thing... Check the stat's AMD's bus in only at 400 MHz top, but Intel's is 533 MHz.
Overall AMD is a better performer, but only because of the fact that they sat down an made the most time efficient CPU...