Honestly, I don't think that some countries would like the idea of bitcoin... They'll ban it in my opinion due to the danger of terrorism funds transfer anonymously as soon as they come to know more about bitcoin.
In some countries yes, and probably bitcoin would remain in online transactions, even if some countries ban them.. there would still be new users of it just like this days...
Yeah, bitcoin has a quality that governments don't have the power to ban it.
But still there will be a possibility, that is; if a country want to ban it then they will block their wallets in the country but still people will use VPN for its use.
If bitcoin is able to surpass the governments regulation then it can become very huge, if it can't then it still be huge. But it will have competion form other payment instruments.
I think/hope bitcoin will go for the latter which will make bitcoin the no 1 currency for me and many other people.