A coworker was checking her upgrade eligibility this afternoon and on a whim, I decided to see if AT&T would allow me to upgrade (even though my earliest contract doesn't expire until December)... as it turns out, AT&T will let you get full discount pricing at the 6-month mark.
Thankfully, I knew that the Microsoft Store online was offering the free camera grip, so I ended up ordering from there. No difficulties doing so, other than the fact that I had to put IE11 (Win8.1) in compatibility mode for the Microsoft Store, because the Submit buttons wouldn't work. I'm actually pretty excited about it now, and I still have my 920 to fall back on should I have any reason to do so.
My only disappointment is not knowing the availability of red and cyan versions, but oh well... I ended up getting a black one, which is good too.