To those like me who haven't heard back: did you also submit your applications within a couple days of the deadline? Maybe they are reading them in order they were submitted.
I also heard of people being receiving interviews and rejections from CMU NGP (though the rejection may have been from a similar CMU program -- I heard second hand) within the past couple days. Yet I applied and didn't hear anything, so it seems they just haven't gone through everybody.
Also, I emailed Brown and they said they are just finishing up and will notify regarding acceptances and rejections. So it seems many places, at least Brown and CMU, may not be done reviewing applications. Maybe this will give hope to others in the same boat, who have heard nothing.