I think we'll get a Caster DPS and a Tank next expansion, for their weapons I'd like to see...

Tank: One handed axe and a chain in the offhand that works like a makeshift shield around the arm when not used, yes it's for Beastmaster.
Caster: Casters are the only role without a hightech weapon so, I'd like to see a giant magitech rifle that can load up spells.