I know Dancers in past FF games have been labeled as a mix of multiple roles, ranging from support, to dps, to even tanking, but due to the nature of the roles in this game and how they are generally portrayed I would personally like to see them as evasion tanks with multiple buffs and dances they use in order to gracefully avoid attacks while retaliating and pissing off their attackers with their fantastic display of movement (AKA gaining threat).
http://www.youtube.com/watch?v=C5Lfb...outu.be&t=1m7s
Dancers in combat are seen gracefully striking their opponent while avoiding lethal blows. Going toe-to-toe with multiple opponents while coming out on top with style.
Multiple locations could be used as influence for the Dancer job, Costa Del Sol seems like a good spot for the quests to take place due to all the dancers in the area, possibly in one of those currently closed off tents as a hidden combat art.
Regardless of what role this job actually becomes in the end, I just hope to see it someday. It's always been my favorite job in the series. DPS, Healer, or Tank I'll play it either way.
Though if this game has an evasion tank one day, I feel Dancer would be a very good fit for it. (Though I might be a bit bias since I played Dancer as a tank in FF11 with very good results.)
I also believe they could be a Pugilist's tank branch perhaps (unless that is reserved for Puppetmaster in the future). Mainly due to their high evasion and light armor/weaponry. If not, then we'll have to wait until dagger classes are introduced to the game.
Here's an ability that could make them slip into the tanking role from pugilist fairly well when you first obtain the skill. Level 30 skill: Fan Dance.
http://wiki.ffxiclopedia.org/wiki/Fan_Dance
"Reduces physical damage taken and increases enmity. Physical damage reduction gradually decreases with each hit taken."
If they are able to implement skill into FF14's mechanics it would be perfect first ability to obtain at level 30.