Something that I would really like to see is a way to modify your scabard. I am not sure if this is based on real history or just myth, but there are a lot of stories were Ninjas, and similar characters, modified their scabards in all sorts of interesting ways. This would be an especially good with the release of Ultimate Intrigue.
Let's see...
- blowgun
- breathing tube, for hiding underwater
- delivery system for inhaled poisons (though you wouldn't want to do that just prior to the breathing tube gambit...)
- light club / parrying weapon / shield
- stepladder
- hiding place for offensive or contraband substances
- listening horn, for overheading conversations behind a door...
and whatever else you can imagine. <g>
Marginally off topic, but in some Japanese myths, the sword was just about the killing, the interesting stuff was often on the scabbard.