Congratulations on getting an interview call.
Some things that you can expect:
Standard questions:
1) Tell me about yourself - Don't read out your resume. Balance it with both professional experience and other interests (non-profit, sports, hobbies etc.)
2) Why MBA? Why Smeal? - Connect your pre-MBA work, your MBA and your post MBA goals. Why Smeal? - Talk about why you want to attend Smeal (again, make it personal, why YOU want)
3) Talk about your school identification research and how Smeal came up in that (part of Why Smeal)
4) Expect few additional questions if you are an international student - How about post MBA employment?
There could be few other topics based on your individual profiles.
Most important thing is be yourself. It will be a discussion and not an interview.
Feel free to let me know if you have more questions and good luck with the interview.