Can’t really show the origin, because I suck at searching this site, but my understanding is that the expansion will have one, possibly two, new masteries, one of which definitely is a dual-wield ranged class. No idea where the aether part comes from though.
What about a class that can carry a one-hand melee and a gun at the same time? In Torchlight you can hold both sword and gun but IIRC there was no skills that capitalized on that.