The only thing they stripped out of Pro was the ability to join a Domain. If you don't know what a domain is, it is like centralized security, usually used at a corporate network. It would seem strange to me for them to use that feature, but if they do, you can't use Home. Home has some foo-foo features that Pro doesn't like Fast User Switching, but I personally would never use that anyway.
If you already have Home, and can't get a straight answer, no way would I upgrade now. Show up with Home until you see it doesn't work. As an aside, if you do have to upgrade, try to get it through your school. Ohio State has an academic bundle for $155 that has XP Pro, Office 2003, and a bunch of other ancillary crap. Those two programs alone would cost about $500 retail.
I know at Michigan you need pro, at least for full functionality, like printing.