Running windows 7 from boot camp on imac...

[zoossh]

Always thought that Windows7 is able to emulate XP natively. So there is no need to install both XP and Windows7.
edit: okay so not so native but its there - http://news.cnet.com/windows-7-to-have-an-xp-mode/
Not used it myself.

initially wanted to keep the xp partition just in case win7 fails. but in the end deleted the xp partition via boot camp and fresh install windows 7 in the windows partition.