Bitcoin is already a global currency, definition of global currencies point that out. Maybe its not regulated by governments, bitcoin can is used in whole world and by that its global. Why we discuss something
that is a fact, we all need to agree on this as a community.
I doubt that the stores will accept bitcoin for payment. It can only afford the online stores. The dollar is recognized and legalized all over the world. The dollars are almost at each person, but you can't legally buy the products in the store for dollars. So it will be with bitcoin.
Bitcoin is becoming very expensive, and value of bitcoin is rising. Can we use gold as payment processor? No we can not, and with bitcoin will be the same, there will be specialized stores for bitcoin, or bitcoin
can find some other higher application. There are other alt-coins that can be used more widely then bitcoin, cheaper ones for the masses, crypto world is making a revolution in global economy and everything
that happen will be on global level, sooner or later.