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.
Green addresses. Look it up. Confirmation can be instantaneous.
There's green addresses, but also all other online wallet solutions seem to have instantaneous and free transfers within their system (flexcoin does, I think vibanko does as well, infamously mybitcoin used to use the feature as a selling point).
Now if someone could come up with a "clearing house" kind of solution that includes all online wallets, as well as exchanges and regular wallets... they would make life a lot easier, no?