It's great for imagination but not the reality! Even though I want this to happen, but I don't see it happening! No Banks or governments will use a currency created by an anonymous person/group to be used as a reserve currency of their economy.

There will be virtual currencies most definitely but that will be not bitcoin or any other cryptocurrencies that we know now. It will be a government created cryptocurrency where total control will remain with government only! Because if we move to a completely virtual currency, tax aversion will be zero/minimal. That's what every government is trying to achieve nowadays.

However, the reserve will remain the same as today, like debt and GDP. A commodity will never come back as a reserve!