One of the main problems the government will have with Bitcoins is that it will be difficult to extract taxes because there is not a centralized entity like a bank that the government can monitor and audit.  Bitcoins could cause major havoc on banks and governments because they could lose control of the monetary system.  A free market monetary system will benefit the individual consumer because businesses will compete to provide the consumers with the best system. 

It will be interesting to see what happens but I think this is great for humankind.