Multiplayer bot support is good. Let's hope they fix some of their interface bugs. If you start a Duel server then go back to the config screen to set a new game type, you have to manually change the Kill Limit from 1 to something else.
You can bind a key to take a screenshot just like in Quake 3. Afterall, they both use the same engine.
Throw this into the console, jk2config.cfg or jk2mpconfig.cfg
bind = "screenshot"
Hope this helps.