How did you not expect this to happen? Office always uninstalls previous versions if you don't check the right things.
I had no options to check. I burned a copy from work and it just went and installed itself and uninstalled Office XP. I hear that it plays nice with 2003 though, so I'm going to have to install that now.
And yea, it's not that it's not working fine, it's just the UI that's going to get me all fucked up. I can't do anything in Word 2007 without fiddling around for a few minutes to find shit.