I have been running windows 7 for a long time now. and most issues has been resolved.
If you have a Windows 7 Pro Copy, just enable the Windows Xp virual Machine if you are afraid or things that might not work in WIn7...
Drivers is not a problem either, I installed some Old stuff on WIndows 7 to see if it will work. If there is not a Windows vista, or xp driver available for some of the things I tested, Use the 98 driver(for some reson that i do not know the awnser to) it works.
Either Rather not partion a drive in 2(it makes it slower). Slap in another drive (atleast a 80gb) and install Windows 7 on that. So that if you want to boot back to XP just change your boot priority....
1 thing tho, make sure the Xp drive or any other drive is not pluged in when installing Windows 7, because it WILL overwrite your old boot up files of the older systems.