I see this "puttering" as the most likely possibility, since if they do hit some level of adoption that starts to threaten sovereign currencies, the GP's option (2) will come into effect.
Maybe some non-democratic governments will become hostile to Bitcoin, but democratic ones will most likely not try to stop it because they eventually do what the people want.
Case in point: even the US Treasury Department's FinCEN bureau recognized enthusiastically that Bitcoin offers "potential" and "holds great promise" to US economy: http://www.fincen.gov/news_room/speech/pdf//20130613.pdf