I got it via email. After my interview, I received an email asking for a midterm grade report (form signed by my professors just saying what grade I had). About a week after I sent that back, I got the email saying waitlisted. I emailed Karin LaRose-Neil asking if there is anything else I can do besides wait and she said to make sure I send my transcript after finals. I think they are just waiting to see if I keep up my grades...
I agree, you should just email or call - it wont hurt and will make you feel better!