Seriously they did not say we would ONLY be getting a heals and tank during the expansion, just saying those two roles would be coming as an answer to the question of why they were only introducing a DPS before the expansion. So the gun class may not be either of those.

and I can't see it being a tank, as tanks have to stay in melee range at all times to complete their task. (don't try and argue this, it's the truth, this game was not designed to accomodate a ranged tank, and a ranged tank is something that the game has to have the mechanics set in place for from the get go) Which means giving them a ranged weapon is a complete waste of said weapon, when its bound to one class.

As a healer it could work, I'd love to see chemist with a mix ability that functions like Ninjas mudras. but then you'll have a gun... and never use it to complete your role so whats the point? With a healer youd actually be making it purely for aesthetics as opposed to mechanics, which is something SE really shouldn't do.

full circle we come back to DPS, I know theirs too many dps already but some weapons can only be done with dps, if you want to maximise the mechanics you can create. Aesthetics should never be chosen over creating an interesting class, because if the class isn't interesting to play; it doesn't matter how cool it looks, people won't play it. (an issue I currently have with Dragoon)