You should get it.................that doesn't mean it's good though
When your sims reach the age of teen they can decide to go to college. college is just like a normal house except for half the tim eorless you'll be studying. College is a must for those wanting to have the new careers like fame or paranormal. And college lets those of you wanting normal jobs to have a headstart depending on how well your college life went. Those who attend college also get more goals at one time so they get 5 or something instead of 4. apart from that it doesnt really offer much. There are secret societies but i have never found one which is a bummer.
Sims 2 university is good because it gives you rewards. like a telephone to the grim reaper which will let you raise the dead or turn the person into a zombie. It also has a conterfeiting machine which makes money but if you use it for to long it catches fire or the police come. Theres also a plastic surgery kit that comes with the fame career so if you hate what your person looks like that will help. It lets you create a band and gives you furniture. And it lets you cook a new meal, ramen - whatever that is.
So to be blunt you dont really need the expansion but it'll keep you excited for a while.