Have you visited the Downtown Phx campus yet? Be aware that it is TINY and comprised of just a few buildings (UCENT, Cronkite, Nursing, and dorms). There are lots of fun coffee shops, bars, and restaurants nearby, and there's a lot of great stuff along the lightrail, but it doesn't have the traditional college campus feel with a big library, student union, quads, etc. like the Tempe campus. Also, downtown Phoenix is known for being "quieter" than other major cities. It is partly due to the heat, but you don't see as many people out & about or sitting outside as you would in other cities.
However, the lightrail is a great resource! It will take you to Mill Avenue (Tempe nightlife) all the way to the trendy parts of Downtown Phoenix (check out First Fridays!). Having a car is really nice for going to the grocery store, mall, and other misc. errands.
Also, like other posters said, AZ has a West Coast feel and people tend to be into fitness and healthy/organic foods. People in AZ are also known for being obsessed with sunglasses- obviously we have a good reason to wear them, though