I also got waitlisted at Penn State, and I have pretty much the same story as the previous poster. Dr. Morrisson and I were emailing back and forth for awhile, and when I sent him specific questions about the program, I never heard back. He said that things might take until April 15th, and since it's my top choice, I might wait it out. The wait list is not ranked but done by subjects, so I think the person who does similar things to you has to decline before they can make an offer. What are your fields of interest? I do 19th and 20th century American with an emphasis on queer and GLBT studies.
One of my recommendation writers currently works at Penn State, and he said they usually make offers off of the wait list. Another friend of mine is in the program, and he said they just had their visiting weekend, so hopefully people will be deciding soon.
Good luck to you both.