For those of you that want to play around with Windows for some reason, you can. Microsoft is providing its Windows 7 Release Candidate as a free download! The coolest part is that the RC should run for about a year before expiring. So if your running OS X and maybe need to run Windows in a VM, you can get it for free for a year and not feel horrible for purchasing a copy of XP or even worse, Vista.
I recommend running the 32-bit version in a VM as it is a little less resource hungry. Get it while you can… The free download will end in June.