Just limiting it to daggers wouldn't save any significant time, unfortunately (not outside of animations, assuming the art isn't already there to begin with).
Once the work required to implement a dual wielding ruleset is in, then it shouldn't matter which weapons a character is dual-wielding (provided you're using weapons that can be dual-wielded). Limiting it to a pair of daggers instead of a pair of swords or a sword + dagger doesn't cut down on the amount of work. In either case you have to apply balancing modifiers and penalties, create an associated skill, etc.
I would like to see dual-wielding in as well, but just setting it up as a quick hack is not the best way to go.
