could they not just run their services off Tor and thumb their nose at the financial authorities like certain other sites and services do, seemingly with impunity?
When you are a business fearing regulation, this is all irrelevent, because you need to make public what customers get in return for sending you bitcoins, as well as your public key, so customers know who to pay.
It would be interesting to see a truly anonamaus bitcoin system. You would need invalidate a coin for which you do know a secret, and create a new coin for which someone else knows a secret, in such a way that when the other person proves they know the secret no one can figure out that the coin they know about is the one you gave them. Giving all of the things already possible, this seems like it is easy in theory. Doing it in a computationally efficient way is a different story.