@phoenix: This will not work. If you look at your traffic you will learn that
the signature (number of connections/second, amount of data transfered,
source, destination, ...) is unique for most p2p applications. Even if
your use encryption it will be possible to detect an ed2k communication
by analyzing the traffic!
The only thing encryption can do is to hide the data from an attacker
sniffing your communication. IMO it's not even possible to prevent
a man-in-the-middle attack, because peer authentication is not possible.
But one thing the providers are currently discussing is scanning the
traffic for viruses, worms, copyrighted material, ... . In this area encryption
will help. In the next step they might think about the more sophisticated
attacks, and we might think about more sophisticated countermeasures ;-)