I interviewed at USC in early November. I haven't heard from them as of yet either. The reason being: I e-mailed Eva and she said that USC has only sent out a handful of acceptances. She went on to say that the school does most interviews in the spring and accepts the majority of the 144 in the spring as well. Don't worry if you haven't heard from them. There still is plenty of time.
i interviewed that day, too and haven't heard anything. last tuesday eva told me that the second round will be decided "in the next two weeks." so i guess we could potentially have another coulple of days before people start hearing back... yikes
I interviewed there last Friday, the 20th and they said the next round of acceptances will be the end of next week, which is this week, ending on Fri, 27th.
Good luck all! (with just a smidgen more luck for me)