Yup

When will the ET's come and save us from the IRS?

The biggest question with taxation comes the valuation. With as widely as Bitcoin's value has fluctuated, it isn't as if there's going to be a good method for evaluating gains unless there is a realization of profits (in US dollars) in its sale - just like any old stock. But you can bet that government will try to use the power to tax to control it.

If the gov't gets more ability to monitor Bitcoin for tax evasion and used in criminal activity, it will be harder to be harder to argue that legitimate transactions always should be done in state-backed currencies. It will be closer to a free market where state-backed media of exchange compete with cryptocurrencies.

I don't see how central banks can hold on for long to their ability to influence aggregated demand using monetary policy.