You're in luck, I've already sent it in and a replacement is on its way back, so if you look around the office mine is there somewhere for you to experiment on. I'd love to know what went wrong!
Awesome! Sounds like it's already shown up in Portland so they're mailing down to me here in Austin. I'll check it out as soon as I can get my hands on it!
Please let me know if you do figure out what the problem was, I'm still worried my game caused it somehow and won't feel comfortable releasing it until I know for sure.
Just FYI: I got the unit on the 24th, battery was dead (no surprise) so I put it on the charger. When it booted up it was working fine and I haven't seen any problems with it since. 
Holding down the reset button shuts down the power supply chip, so it should have the same effect as draining and recharging the battery. Maybe a longer hold would have done the trick? We'll give that a try if this comes up again. I don't love the idea of telling customers "okay, just wait a week for the battery to die then recharge it, see if that fixes the problem".
On the one hand I am annoyed that we can't get an answer as to wtf was going on, but on the other hand at least there is a fix in case it happens again.
I am just annoyed because I tried real hard to get that thing to run its battery down whilst I had it here and it just kept on truckin'! Oh well.