A lot of proponents for bitcoin would trout anonymousness as a feature rather than a threat. It really depends on your point of view. If you're a privacy advocate, it's a good thing. Law enforcements and anti-money laundering people thinks it's a bad thing.

I believe Steve Gibson, of Security Now, called it the "crypto-dilemma". On one hand, it could be tool of political activists to resist repressive states such as China and Libya. On the other hand it could be used as a tool to launder money from kidnapping operations and organized crime activities.

If bitcoin succeeded, we will all have to live with the consequence of the new technology. For nation-states of all stride, from authoritarian to democratic ones, it will be a devastating attack on their power. It will give power back to the individuals. For some of us, that's what we like to see.