I think Mr. Happy already made a small list of what they said from the livestream.
If I recall he said they will build up charges (much like warriors do for their stuff) and then spend those charges on big attacks with generally longer animations or wind-ups. So think of it like, finisher combos with much more painful and flashy numbers I guess. That said, they will MAYBE be joining dragoons on the floor as players will try to use those skills only to find themselves stuck in an AoE after clicking it. Still cool idea though. Totally will main that class. Only question is, do I main it immediately at launch and lvl it up or get all the way to the end of the expansion first and then level it up? Decisions decisions...
Also, while I'm honestly shocked they are using monk gear instead of dragoon mail gear, I love the edo period style of no/little armor and more speed/power. At least I think it's edo period... I'm not Japanese, I just fool myself to thinking I think I know stuff.