Yes, I am trying to help.

I'm slowly (very slowly due to other stuff) working on a packet filtering program for JJ2 servers. At the moment it sort of works, except for a lack of filtering and some problems with listservers. Current rough status and todo list:

Done:
* Intercept and near-transparently proxy client UDP and TCP connections to JJ2
* Support multiple clients

Critical:
* Add filtering code (I've got this planned out, just need to write it)
* Handle 'blind' UDP packets (e.g. pings)

Useful:
* Add logging
* Add kick/ban support (JJ2 will ban all clients when using the filter)

Nice:
* Add plugin support (plugins will have full read/write on all packets)

At the moment I don't have a release date, however I will inform everyone nearer the time.