(I am not modding you down.)
It's fortunate (for Bitcoin) that governments and ISPs generally move at a sloth's pace. If it comes down to an arms race, they can't win more than extremely temporary victories. If they could, they'd have completely stopped filesharing over Bittorrent, IRC, AIM, MSN, Skype, HTTP, email, Usenet, various P2P services like Kazaa and Limewire, ... and so on.
If they start blocking/interfering with the protocol (like Comcast injecting RSTs into suspected torrent connections), you can just encrypt the entire transport layer and randomise the ports. People were configuring their firewalls to drop the falsified RSTs from Comcast.
If they blacklist hostnames, there's a near limitless number of them that can be generated. The client can precalculate a domain and ping it at a given time for instructions the same way botnet clients work. The government can't register/block every possible domain name that will be generated. Another alternative: http://en.wikipedia.org/wiki/Fast_flux There's nothing illegal about having a hostname resolving to an IP.
> Especially if the software is open source, as Bitcoin is, all the knowledge of the inner workings of the protocol is public knowledge
This is also true for GPG, ciphers like AES/Twofish/Serpent, etc. Openness does not necessarily imply weakness.