I don't think nationalisation of Bitcoin by any country is right thing to do. This will leads to concentration of mining fields in that country and country will partially become ruler of Bitcoin. We all using Bitcoin will be subject to policy of that country's rule. So rethink!
Isn't it happening right now? every country has a different view on bitcoin and have their different ways of handling it. some country may not even care right now but if the popularity of it boost on their country. they will certainly regulate it. a nation to start adopting bitcoin as their national currency is a long way to go. the hardest part on that is when the central bank should create a reserve first thats why a large amountnof money need to be invest first on bitcoin.
Regulating the bitcoin is certainly a paralysed idea. Suppose my country is keeping the complete check of transactions within the country, how can you say they will peek in my wallets whom I am hosting on VPN/Proxy, etc. It is just a sweet dream away for Bitcoin reality made by some immatures.