I've said it before and I'm sure I'll say it again: the biggest risk to bitcoin is a government (specifically the US government) deciding that they don't like it. Barring that, its growth will likely continue.
You don't need to be a prophet to guess that. Of course they don't like it. To me, it's not even a question. The question is, what are they gonna do about it and for how long will they manage to delay Bitcoin adoption.
My thinking is along the same lines. They're tacitly accepting it now, not because they accept it, but because they think it might collapse on its own. When they realize that it's not going to go away, I'm almost certain that the government will step in somehow and try to put the kibosh on bitcoin. How long that will be is anyone's guess.
