Well... I'm not a student at UPenn yet, but I thought I'd share my experience.
Despite the rather awful wait to hear from them, they have been fantastic since I was accepted. When I got the phone call from my interviewer (the anatomy professor), he told me to remind him who I was on the first day of class so that he could get me in contact with people he knew so that I could do research I was interested in. I've talked to the director of the VMSTP, who was incredibly helpful and willing to answer all of my questions.
I've been talking to some people about taking a year off to do research, and I got a call from the dean of admissions (note: I had only told him I was considering deferring) today asking me about my decision and giving me the name of one of the professors that might be interested in having me in his lab.
I guess I may be a rare case, but I have felt very welcome and everyone has been so willing to help me - even when I didn't solicit it! I am extremely happy with my decision to go to UPenn 🙂