Hey guys, I copied this out of an email sent to me soon after my interview...hope it helps!
"I'm sure Kathy told you a little about our notification process but to reiterate... a decision will be made on your application by the end of the month [i interviewed in February]. If you are accepted, we will send you an e-mail before March 1st, followed by a formal letter of acceptance. If you are offered a spot on our waitlist or if we determine that we won't have room at all, you'll receive a letter in the mail towards the middle of March. Our waitlist is a very active part of our rolling admissions process. If you have any questions as to how that works, please let me know."