Thanks guys, that's what I wanted to know. Magnus appreciate your "comments". If you can't offer anything helpful than don't reply.
I don't think Microsoft has ever supported dual licensing with OS's (I could be wrong, as I only have done licensing with XP and Server 03 and up.) Unless you own a volume license, it's one license per processor, or one per machine.
But as stated above, you can call and have the "limit" they set on your license removed. I always tell them the same white lie of "I had to reinstall Windows after my processor blew up..." I don't think it really matters what you tell them exactly, but I never had an issue calling them to reset/remove the limit.
As far as getting a discount through your student status, I can't see why you wouldn't be able to purchase one through your college. I purchased Vista, Server 03 Enterprise, Web Server 03, XP, Vista, and many others when they were available, but it may be a per college thing, and not a Microsoft thing.
Good luck, and enjoy Windows 7!