I think from the leaks I've seen that University is definitely coming. I'm really hoping that I can attend class with my sims. I'd love a University that is an away from home world with dorms and apartment living and a whole new theme for my sims that want to do a 4 year college. I'd love to see local community colleges as well as online classes my sims can do in the evenings when off work.
The thing I would LOVE to see is active high school, I'd love to go to high school with my teens for the first time. I think that would give more depth to the teen life stage. School is a huge part of the lives of child to young adult and it would be pretty impressive if they finally opened that up.
Other than that I'd love for them to finally allow us to have an active career as professors. All ages of sims with active school and the teaching/professors active career would be all a University/School ep would need to make it pretty amazing.
Edit: I'd also like to add that I really hope they would put something into the calendar for school holidays. In my calendar I have like a couple weeks for summer break for my kids/teens. A week for Christmas break. A week for Spring break and a few days break for Thanksgiving. It would be nice if I could actually designate those as school holidays somehow. Just maybe put an option for the holiday and let me pick how many days it lasts rather than making one each day. I do play on the longest seasons though and I age sims up myself so maybe that wouldn't work out for those who don't. It would be a nice option though.