Ideally an expansion would be a bunch of new zones, armor, weapons, and the like. But that is impossible given the Living Story taking up the majority of the resources. It is what it is, and the game just isn't going for that. I'm good with it overall.
My only real disappoint is that weapons & armor will probably continue to be either gem store or super-rare drops from World Bosses. And since they're being sold as such, they'll likely continue being flashy things like we've seen so far.
In comparison, one of the really nice and understated things about Nightfall and Factions was they introduced tons of new basic weapons and armor, and not just uber flashy end game stuff. Factions had everything from katanas to weird stick-swords. Nightfall gave us tons simple scimitars, jeweled shield, harem pants, and the like. None of which was flashy, and nothing anyone would likely pay Real Money for.
Its hard to see things like that fitting with the GW2 / LS / Gem setup, and its disappointing to think about.