if you have an edu email account, you can see if you are eligible for a student copy win7 at $30.
http://windows7.digitalriver.com/store/mswpus/en_US/DisplayHomePage?resid=xx2UZAoBAkYAACtVDSUAAAAw&rests=1256831030346
It is the same as the retail versions, either home premium or professional, 32 or 64-bit.
I got mine a couple of days ago, and win7 is lot better than XP. Comparable to snow leopard imho.