Well, before I went for my run, I was examining the envelope, and I noticed that it seemed to have something other than just a letter. Putting it up to the light, I noticed what appeared to be a small envelope or something that was not letting much light through. This elevated my mood somewhat, at which point I went to run.
Came back, got dinner, went to my friend's place, and finally, just now, opened the letter. So, inside was a card with admitted/provisional admit/alternate check boxes. The alternate check box was checked on mine. The letter states that many alternates were offered acceptances at a later date last year, but goes on to say that they are not certain about chances of admittance from the alternate pool this year (almost 2k applicants this year, highly competitive, as we all know).
Though it would have been awesome to have been accepted, I knew it wasn't going to happen since I didn't get "the call." However, I am grateful to at least make the alternate pool, although this does mean more waiting (been waiting six months!)
Good luck everyone!