For now. Governments are catching on, and since the transactions are public, they can (and are putting the building blocks in place now) easily apply the same regulations to international bitcoin transactions as they do traditional money transfers.
Basically, folks today are taking advantage of a blind spot in government oversight. They're aware of it and are removing that blind spot.
I heard an analogy at one point - governments are elephants. It's usually pretty easy to avoid being stomped on when you're small. But if you do get stomped on, you'll be utterly destroyed. Many governments have no problems with making examples of people.