I hate to say this but this still suffers from all the issues that previous suggestions for point of sale stuff has, in that it takes a great deal of time comparatively to confirm the transaction is actually valid. People aren't going to wait around for a quarter of an hour after buying a stick of gum to wait for a transaction to verify.
People also aren't going to bother spending hours of their time or thousands of dollars trying to execute a successful double spend just to steal a pack of chewing gum. Accepting without any confirmation in such a circumstance is probably lower risk than letting people pay with credit card.
This is a great step forward and nice video. When the time is right, we'll want to integrate this (or something like this) with bit-pay.com.