I think we're a long way from efficient quantum computers that provide real benefits over current systems. However, I think security will have to evolve as computers become more powerful. In terms of Bitcoin, I do not see any real threat.
I think I read that someone might have invented a quantum dot, but that's a very long way from a quantum computer. Considering that a modern laptop is way more powerful than a whole mainframe system from 30 years ago there might be quantum computers in another 30 years.
Yes I agree, however the government might have quantum computers for all we know.