As announced earlier this week, Maxis held a chat about the Sims 2 University last Thursday. The expansion pack has shipped and so almost all information that was given during the chat is old. The new information is that Sims can move to another college in town, as they're put in the Student bin when you move them out. This bin is shared between the colleges, so you can move them in anywhere else and continue their education. There's also the cheat to increase the number of allowed floors:

setHighestAllowedLevel [X] where X is a number that sets the maximum number of floors you can have.

To get to know the rest - if you don't already - read the transcript for the info.