AMD's CPU virtualization technology (formerly referred to by the code name "Pacifica") delivers CPU efficiencies to traditional software only-based virtualization approaches. AMD I/O virtualization technology complements and extends these efficiencies by providing mechanisms to support virtualization software in managing, partitioning, and securing I/O devices, which is anticipated to result in improved performance and less implementation complexity in providing I/O in virtual environments.Sounds like this capability will make hardware abstraction layers and drivers more compatible with virtualization, and done well, it probably should increase I/O performance quite a bit. Off the top of my head, I'm unsure whether this tech is a direct competitor to Intel's I/OAT, and all of the platform talk in Intel's press release is no help.
AMD expects all of its CPUs to support I/O virtualization by the middle of 2006, and it hopes to see core-logic chipsets supporting the tech by the end of '06. The spec itself is supposedly available from http://developer.amd.com.
If you're interested in playing more with virtualization tech, you might also be interested to know about the free version of VMWare Server that's just been announced. It's not open-source, but it is free of charge and shouldn't be a bad way to begin playing with running multiple operating systems simultaneously on one system. Of course, I used to run the MacOS as a client to the Amiga OS on my A3000, but I'm just old.