I was wondering if we find out how to insert new models into the game. Boba fett would me my No 1 pick.
I also found a strange dialog in one of the .dlg files while using the NWN Explorer. It was a dialog between your character and CHEATBOT 9000. It lets you change hardcoded variables in the game, warp to another planet without cheats, add star maps to the ones you have, add an npc to your party, (This part interested me the most!) and change various other things in the game. I forget what the dialog was named though. It seems promising!