I've had one interview so far, so I suppose I can't complain, but I do feel the same as you. I applied to 15 schools, and have heard from two, one being the interview, the other basically telling me that I've been put in a pool of competitive applicants for later review, which to me seems like they've just brushed me aside until they have the full pool of applicants to compare me to. It really doesn't help that my parents ask me if I've heard anything on a daily basis, and that they've went out of their way to scare the crap out of me about it. Today my mom says "You really have a lot riding on that one interview, you don't want to be in that position. It would be very upsetting if you didn't get in." I ask, you mean that school? And she says, no anywhere(sorry, needed to vent that).
I don't know how strong of an applicant you are, but I feel I'm pretty strong, with a 3.92GPA, 34Q, and a decent amount of volunteering, leadership, and research under my belt. I have a friend who's got similar stats, plus even more research, and lots of extra curricular to boot, as well as double major and she hasn't heard anything, and another friend with good stats, who just completed a his masters at a medical school, and he hasn't heard anything. From everything I've heard, this waiting game is normal, and it seems that a lot of schools, despite rolling admissions, like to build their applicant pool and interview later. It would be nice to get statistics on this.
Just make sure all of your applications are complete and under review. One of the schools I thought I had applied to fairly early informed me my app wasn't complete when I called. One of the essays somehow wasn't marked as submitted, even though it had the thing saved from my submission, so my application had went nowhere and ended up being the last one I had officially submitted. I've also heard of schools not receiving letters of req, holding the app back, and clerical errors, so it's always good to make sure with a phone call that everything is in order.
