But leave that aside, you said you like government-managed currency and I believe you. Venezuelans don't. The way I see it, what's stopping the EUR and USD from going down that spiral is momentum, rather than some law of nature.
I'm not convince the issuing schedule for BTC is ideal either. Grin, to pick a cybercoin which has some interesting technical innovations, issues one coin per minute, forever, and since coins are lost, this might be better.
But I like the idea of a transnational currency, where no one government is in a position to change the rate of issue, and I think Bitcoin has real potential as a refuge for value to flee to, in the event that the increasingly reckless experiments which Western governments and their central banks are making with their currencies come back to bite us.
Don't think it would spell the end of sovereign currencies, either. It would force them to be more honest, though, and that would be a good thing.