I can clearly see that there are other cryptocurrencies that are beginning to dethrone bitcoin, showing off there quick and secured transactions, though bitcoin continues to be the king. What does bitcoin need to improve state your opinions.
I think there is nothing to fix with bitcoin, because bitcoin is very good, but only one is possible for us with the problem of delivery that sometimes, long to wait until 6 confirmation ...
The legality in other countries and of course the security of people, clear regulation.