Another day, another way to run Windows on your Mac. Parallels Workstation 2.1 (free) beta for OS X will let you run any OS “virtualised” so you can run it in a sandbox along side your other OS X apps. But because the Mac uses an Intel processor it’s nearly as fast as running natively (ie with Boot Camp), especially on the iMac and MacBook Pro which have Intel’s VT support enabled (on the Mac Mini it’s all done in software – but it’s still no slouch).
But I can now see the point in Boot Camp: Half Life 2 (the virtualised solution doesn’t support 3D graphics). And there is of course still a danger in virtualised Windows support in OS X: will developers bother with OS X versions of their software when the Windows versions already run in the Mac environment?