I would think that there is some kind of system indicator that will allow the items to be sold at retail after midnight. I've been to "Midnight Madness" at WM for both TPM and AOTC, and it's actually run like clockwork at each. I was in a 24-hour SWM one night around 12:05 AM for something completely unrelated, and one of the clerks said that they would have to wait until 12:10 for the computer to reset. Apparently (at least at this WM) the WM central computer resets around midnight for the "fiscal day" and I think that this same kind of approach will probably apply to the ROTS toys.
I had typed a rather long rant on how WM is exhibiting a tendency to view the SW toy section with spite, but it wasn't relevant to this thread, so I deleted it. I guess what I'm trying to say is that WM's HAL-9000 unit that controls the chain will have everything working wonderfully at midnight and there will be no problems whatsoever. Just be sure when you discuss this with your friends, you realize that the WM security cameras in the parking lot can read lips.