a few things.
1) Conquest mode is a long-term game where to try to bash as many enemy sectors as possible. Takes out all the fun, i know. I don't play conquest mode for one simple reason: DYNAVERSE. Dynaverse servers are the same thing as conquest mode except with other human players.
2) If you play normal campaign instead of conquest you'll get story-related missions. Quite fun.
3) If you play conquest mode, try base assaults, planet assualts, homeworld assualts, etc etc.
4) You can download new mission scripts made by fans and add them to your game
Wheee! New missions! I've downloaded about 6, PLUS 2 updated versions of the old missions, all fan made. But back up the original stuff so you can play on dynaverse servers as most require you to have the originals in, unless you play on a modded server.