Technically speaking any country could launch a crypto-currency. In a lot of developing countries it would be a good idea to adopt an existing one or develop a new one. Big cost savings and they would be ahead of the curve technologically speaking. Would be cool to have US Coin or Canada Coin for us North Americans. Realistically I see it being like a dollar, and then a bunch of cournties would make their own varient of that coin zonally. Not that it makes a lot of difference, but hey, thats the way they like to operate.
If a forum or company can create their own currency, then why a government cannot, to me i think that in future we will see that governments will take more interest in crypto currencies and will therefore create their own currency which they will allow their people to use and exercise it in their country.