We cannot do anything if governments decide that they will ban bitcoins. But as long as they are not making any moves in banning bitcoin. I think we can do all we need to do to earn good amount of money in bitcoin.
I also agree with you when the Goverments ban bitcoin we will have difficulty in trading bitcoin. I think then price bitcoin will go down more in short-term and many transaction have affect by bank. But long-term price bitcoin will go up because Bicoin becomes developing in economy when it is banned. Although Goverments ban Bitcoin, tendency of the world use Bitcoin is not bunned. So we don't too worry about it.