Virtualization is the way forward, forget Boot Camp. Virtualization is all about nativly running multiple OS at the same time – no emulation, no reboots, no loss of speed.
I’m betting virtualization will be in OS X 10.5, Apple already announced that Boot Camp wil be built into 10.5.
If you want to try this out already Parallels has a beta out for its virtualization software. Get it while you can.
Edit; Just found a Wired article on the same thing that has a load of screenshots too. It’s worth a read.