EDIT: in retrospect I should have posted this in the main thread rather than make my own. sorry for clutter!
I was initially really excited for our new ability. WW's lack of cleave in 2 and 3 target situations is my biggest gripe with the class, and 120% damage in these situations would be great, especially with an old school ability.
However then I got a thinking: the ability, as written, only seems to duplicate special attacks and not white damage. So in a 2 target fight, 60% of normal damage plus 60% of special attack damage ~= 100% of normal damage. Does nothing to increase our dps, just spreads our damage in a way similar to tabbing between targets. Additionally, the ability seems to be balanced around NOT ever being a dps increase. Since as currently written, we can pop the ability on a single target, it can't be set up to increase our single target dps (which is high compared to other classes). I'd also doubt that it would increase our dps in aoe situations through spinning crane kick, as it seems likely that the mirrors would only damage 1 target.
It feels like a cool ability that as currently implemented is useless. WWs need a dps increase in 2 and 3 target situations, and this does absolutely nothing to address that. Going to be interesting to see how it changes on the PTR. The only fix I can think of is if the mirrors do ALL our damage, but cannot attack the same target as each other or our main character.
As of now (obviously based on rampant speculation), I'm pretty disappointed.