I hope they do make another Jedi Knight game and that it has the following.
1. Scalable models, so characters are the right size in MP.
2. An option for single, double (two single) or a duel saber like Maul's and that the option's available could be set server side and client side but servers would have ULTIMATE control of that.
3. Keep guns, but make the game (SP) and types (MP) revolve more around the saber.
4. Implement defensive features like those in promod, and make sabers more deadly.
5. Have more team based game types for MP.
6. Add campaign style feature to SP where you start as a padawan/apprentice being trained by a MasterJedi/ SithLord and have dynamically generated missions to complete. As you complete training and missions you skill increases. This would greatly enhance the replayability.