it wont be sold out, just wait till you can see if it will be possible to run on Tmo. They are putting some added restrictions on the process, different than last time.
-activations are done in store unless you buy through apple.
-also their are rumors that AT&T will penalize people who do not activate within 30 days.
so just wait and see, it most likely will not sell out as they will have a ton of them. If they do its only temporary.
"A computer lets you make more mistakes faster than any invention in human history - with the possible exceptions of handguns and tequila." - unknown