Have to admit, I did get a kick out of some of the combinations.... that said, after a while it did get somewhat stale. I agree with all of the 'add user content' and 'add world view' ideas out there, if possible those should be added.
now... for things I would have added....
Warrior + Firearm = Marine
Assassin + Firearm = Agent
Agent + Cigarette = eh... Solid Snake?
Warrior + Warrior = Corpse + Corpse + Blood (sukaz)
Warrior + Beast (or dom. animal maybe?) = Knight
Knight + Dragon = Blood + Paladin! (had to...)
Sex + Life (or people) = BABIES!!! :D
Demigod + MOAR ENERGI!!! = Game Over (demigod kills you and becomes the new doodle god)
 "Doodle God"){kind=icon}