Speculating purely for the sake of it...and I have nothing better to do at the moment. Take from it what you will....
Daydreamer said that letters are being sent out, but per Blondies phone call, they are sending emails out this week. Not to say that either one of you are lying, but we seem to have some conflicting information!
Blondie, have you gotten an email yet perchance?
Just going off the information we have gathered on SDN: one person got a phone call, the rest have heard nothing. BlackDog maybe you are right, and Blondie was offered early admission? My initial thought was that Blondie seems to be a very eager and passionate person, and maybe someone on the adcom picked up on that and wanted to give her a heads up 🙂 ... But it appears that based on what she was told in her phone call that they were going "down the line" which implies that they were making many phone calls. Also, it doesn't make sense to me that they would suddenly send letters rather than emails. All the rejections I got were by email, except for one. From a purely economical standpoint, it is cheaper to send emails than mail letters to all applicants. And why would early admissions get emails but not letters? GAH.
BlackDog, did you get anything else yet? Email or packet?
Anyway, just tossing some ideas around. On another note, the longer it takes me to get a decision, the longer I am going to stress eat for. I would like to dedicate half of the giant bowl of ice cream I am currently mowing down to the terrible 12 hour workday I just had, and the other half to AVC <3 😀 What's a few pounds in exchange for admission, right?!
I hope you get good news soon. The waiting game is brutal. 
