If there have been both rejections and acceptances and you still haven't heard anything, there's a chance that you're on a waitlist. What sucks about this process is that when people are on waitlists, they often never know. I find that very cruel, because people tend to assume that they were at the bottom of the barrel, when in reality they could be in the final round!
A friend of mine is a professor who is currently doing admissions and she says that people are frequently waitlisted without being told -- they are only told if the spot opens up. If the spot never opens up, they never know that they were in the final round.
Even if we are going to be rejected, those of us who were waitlisted should at least know THAT. It is a lot more encouraging for people who are thinking whether or not they want to give it another shot next year.