get yours today! Oh, and this is not a beta.
http://switch.atdmt.com/action/IE_7_Windows_XP_SP2_B
(its the link thats on MS's site, no really, see for yourself -- http://www.microsoft.com/windows/ie/downloads/default.mspx)
I'm installing it on my XP Pro Virtual PC right now.
Speaking of which, Microsoft Virtual PC is completely free: http://www.microsoft.com/windows/virtualpc/default.mspx
And they have a 2007 Beta version available too.