that's right they are panning to put taxes with exchange so they can benefits with btc, might be much better instead of banning bitcoin we should be happy if government will place some actions to make some earnings too like taxing local exchange in our respective countries in this way adoption or recognizing bitcoin will be much possible in every nations.
That depends on the government. If they think that the benefits (tax revenue, reduction of crime.etc) will be more than the drawbacks (tax evasion, dark markets.etc), then they will legalize and regulate the Bitcoins.
If the question of legalization of bitcoin will be very serious, the authorities will have to find ways, and users will have to pay taxes.