Okay, I know no one probably gives a crap now, but I'm gonna update my situation just so no one either ends up having the same thing happen or assumes that they'll be split up.
I got to NYU (where the auditions are, for those unfamiliar with the process) with my teammate, and once we realized that the other person in question wasn't showing up, we explained to the casting people that we weren't supposed to be on a team with said person. A call to the third teammate revealed the problem: apparently said person misread my handwriting: I ended up writing down the email addy on a piece of paper for him (which I put in brackets, which he put in the subject line, complete with spelling the email addy wrong, although it was on the damn application in the first place). Luckily, we were able to get a rescheduled date (TBD).
The moral of this story, folks? Don't pick people who aren't too bright for your team.