I don't think there will be global regulation of bitcoin or other cryptocurrencies.
Because some countries have declared bitcoin legal, there will always be disagreements between the rules of each country, and I think bitcoin will have a very good future.
I do think so that this thing will happen but this will definitely take lot of time for this world to understand the real picture of the bitcoin and other crypto currency. Most of the people still think of it as a scam and that they are not accepting it and are not even interested in investing of their money into it. With time, they will realize the worth of the crypto currencies and will surely stand for crypto currencies.
Bitcoin global regulation is the best thing to do and that if we managed to do so, then there will be likely chances of bitcoin to become the global currency as well because doing so will result in making lot more people aware of bitcoin and that they will then be investing their money into bitcoin as well. This will no doubt take lot of time and that lot of efforts are needed to be done as well to make things happen this way.