There are many weapons in DDO that are currently used very little, aside than by spellcasters looking for the appropriate spell enhancing property on them.
To encourage wider use of weapon types, and to encourage more use of tactics and thought in combat, I suggest that weapons be given inherent properties.
Here are some suggestions for some of the less popular weapons.
Daggers A stackable 5% bonus to attack speed
War Hammers A chance to reduce the fortification of the enemy struck with it. (Although this would need more enemies to have fortification, something that is long overdue in the game).
Shortswords A stackable +1 sneak attack bonus
light hammers/light maces A stackable +4% to stunning
Battleaxes A small percentage chance to bypass fortification on critical hits
Sickles Inherent bleed/slicing property
Heavy Mace Inherent lesser destruction (-2 AC on hit)
At the moment damage is the only concern of players and there is little reason not to use a rapier, scimitar, or khopesh. The above would redress some of this balance and do so in a fun way that encouraged difference rather than sameness.