I do not think it could be used as a world currency, because its value fluctuates frequently. I hope it is still a high value currency and is a long-term investment and a great profit for everyone.
Well it could be used as a world currency and it also couldn't be used as currency because bitcoin is not yet implemented legally so we couldn't tell when it would gonna be used as a world currency. But I'm very positive that bitcoin would become or would be used as a world currency maybe not now but I hope it'll be soon.