Realistically, nerds better get on telling their parents and grandparents about this funny money sooner than later, because once government informs an older person on how to think, it's pretty much done.
Till they die.
Yes, even if it stays restricted to nerds and finance types with an anarchistic streak (of which there exist a lot these days), it might succeed in the same way Linux succeeded. In the background. Unlike the mentioned alternatives, bitcoin is not a company so it can afford to stay a niche a long time.
I think it will slowly be adapted, a lot of support infrastructure for merchants still has to be made but on the other hand there is a lot of international momentum going. More than for any alternative currency, ever, I think.