Bitcoin is still in its infancy. As of TODAY, it is too slow for retail transactions like a grocery store. But if Bitcoin continues to gain acceptance, there will soon be a whole ecosystem built around Bitcoin. I can see merchant processing companies that will step in and fill the gap, to help process retail transactions instantly... and these companies will carry some burden of liability & insurance on their shoulders. It's really too early to tell what the Bitcoin landscape is going to look like in 5 years. Remember that when credit cards first started, merchants had to carry a printed, physical book that was updated every few weeks, that listed all the credit card numbers that shouldn't be accepted! Crazy, right? But that's how it was at the beginning. Of course, the credit card companies would honor the transaction for the merchant as long as the number wasn't listed in the book, so that was the merchant's protection. Someone will come along and offer the same sort of merchant protection for Bitcoin. That's assuming that Bitcoin becomes viewed as a legitimate form of currency by the mainstream, and not just a hoarding mechanism for speculative investors.