I received the email offer at 2:30pm EST. I think they are indeed going through a rolling admissions, meaning that if you didn't hear early, you might have to wait a while as some others decline the offer - which I know quite a few who got in are likely to do so. Anyway, don't lose hope yet - best of luck!
Just got into MIT Biology - cool program! It was quite a long wait as I was interviewed on Feb 24. Thanks to elanorci and NoCoffeePlz and many others who were of great encouragements in the process, and good luck everyone!
I think I will make a final comparison between Columbia C2B2 and MIT Biology before deciding where to go (I am applying for CompSysBio tracks and C2B2 is reaaally a good one) - most probably will move to Boston in the end...
Hope to meet some of you guys there in the fall