While, at least until Windows Vista arrives, you won't be able to dual boot Windows on the new Intel Mac hardware, it now appears that you will still be able to run Windows. Yesterday Microsoft committed itself to a release of Virtual PC for the new Apple Intel platform.
Considering an entire layer of emulation can be removed from the product, the new Virtual PC should run Windows software at almost native speed. The downside is that Microsoft did not announce when it would ship the new version, and while you're waiting for it, you can't run the current release under Rosetta.
Although thinking about it, that's probably going to be for the best. If you could run Virtual PC in Rosetta it would be a huge resource hog. Native x86 code would be running in a virtual machine emulating a PowerPC, on-top of another layer translating the emulated PowerPC instructions back to native x86 code. Anyone want to take bets on how slowly that would all run?
Update: More from Apple Insider...