Also, if you are a WCU student, it looks like you can get Vista Ultimate for $15 (DVD). Might mean you can get Windows 7 Pro for that much once it is released. I know my brother-in-law was able to get Windows 7 Professional from his university for $10, like 3 weeks ago. Full Version, no restrictions.
*edited* me for never putting links in: http://www.wcu.edu/10608.asp