I think we have good example of Japan, who are economically too much strong, they regularize bitcoin, and i think still too much successful. Therefore i am sure that other countries will also regularize bitcoin very soon. In fact it is depending on the number of bitcoin users, if the users of bitcoin are increasing from time to time then they will surely compel their government to turn bitcoin as legal currency, because it is the need of the modern time to have a online currency which we can easily use throughout the world.