Bitcoin will not be the national currency of a country, because to be able to made as the currency required many considerations to be taken by a country, while the country currency is a legal means of exchange set by the law made by parliament.
Do you think that bitcoin can not be legal means of exchange set by the law and approved by parliament?
Why not?
I do not believe that some big country will set bitcoin as main national currency, big countries tend to control
what they can. There are many small countries that can benefit from accepting bitcoin, and regulate it to be
their national currency.
Before anyone says that this is impossible cause bitcoin volatility, or number of bitcoins in the end will lead to
deflation is wrong. All currencies fluctuate that is first, why you can check if you wish. Banks and governments
are saying that inflation is better then deflation cause they control the money printing and they always have for
their officials.
This is a question for real experts, and most of the comments in this topic are one line statements without
arguments and explanations.