I'd like it if DNC actually danced during combat. My own variety of they'll-never-do-this would work like so:

Two(or more) dances, think stances. One focused on damage and one on debuffing at the least.
Several steps, think Summon I / Summon II / Summon III in that once you get a step by leveling or quest you have that level of step available during any dance. These steps would be something like Attack Step, Lame Step, etc.
Using the same type of step in succession chain-boosts their effect/power, but there could also be special combos too. Getting stunned/paralyzed/similar would immediately break the chain or combo.

Now, the idea is that you don't use weapon skill abilities, just steps(though there could be some all-dances WS steps too). What happens is you can queue up to X number of steps, and on each GCD tick you automatically execute the next step during the dance. This would let the dancing animation flow without sudden jerks as you fired off an ability, and be an interesting variant on GCDing(bonus points if your skill speed directly affects your dance animation speed). Later on you could get an ability to cancel your most recently queued step, but add a chance of Stumbling(reduced step effect/power for X seconds?) the more you try to backpedal. Depending on your dance, it would affect the step/move performed; say during attack dancing, attack step produces Blade Dance which does high damage, but during debuff dancing it's Kidney Stab with less damage but a small slow effect. As for a weapon, I'm thinking thin fabric sashes, connected to a pair of hand-held ring blades.