What I'd like to see, off the top of my head...
More pool powers - I really enjoy how the sorcery set gives flavor to my magic users, and would love to see more like that to help flesh out the other archetypes. I have a bajillion alts, and the more pool powers available, the better to differentiate them all.
More non-city areas -- Croatoa, Striga, Cimerora, Nerva and even Perez Park do a somewhat decent job, but would like to see more unique environments to explore. A desert. Somewhere snowy. The long-awaited moonbase. Kalisti Warf looks nice and all, but dang I don't need yet another city zone.
Updated cars, monorail trains, and citizen models -- These things are everywhere, so having newer, crisper models would benefit the look of every city zone they're in.
More costumes -- in general, this is always good for the game.
Thanks for everything, Homecoming team!!!