Actually... only SOME people had their orders canceled! Mine has NOT been canceled. And there are others on the Green Lantern Corps Messageboards that ordered this time and have not been notified of cancellation, either. In fact, when we check our orders on the TRU website, it says under order status: Item(s) on hold until release date.
I'm thinking that what happened is they took more pre-orders than they had figures for, and canceled all the orders placed after 2,814 of the figures had been pre-sold. For example, maybe 3,500 orders were logged by the system before TRU pulled it from the site, so the final 686 people had their orders canceled. First come, first served and all that. Just a theory, I could be wrong.