This is an Intel thing, so I doubt you will see this technology in amd processors anytime soon....
The technology is basically the chip is coded to handle mulitple operations as if it was a dual processor system. There is a much more techmology version of this answer floating around here in a thread by look4dlz or something from about 2 weeks ago. Very good reading...It weill explain the technology in depth...its advantages and possible disadvantages...its requirements by software, etc....
The hyper threading in the p4 3.06ghz will be a revised version of the HT already implemented in p4 xeons...whether this is good or not may need to really wait until nov 14th when the p4 3.06ghz cpu is supposed to arrive...