Add additional unique zone events.
Make the casino in St. Martial a chill meeting place with unique npcs hanging around. Make it also the place where you get a day job for bonus reward merits when you log out. Something like "Gambler"
Add a Siren's Call-esque Bounty System in Grandville (opt-in). Might give the feel of a villain being number 1 and always having challengers (afro samurai!).
I would be happy with Grandville getting graphical optimized too.
Add sharks to the surrounding isle's water. Something Captain Mako related, plus backstory/lore.
Villain Epic Pool Powers get a fifth power, Summon their actual patron.
Add/finish moon base / rocket pad. Make it in to pvp zone where shivans & battalion and players fight to control entire alignment buffs/debuffs a la other pvp zones. Heroes win, every hero in every zone gets a temp increase in something power, same for villains, rogues, vigilantes, maybe praetorians? Add a setting which allows players to turn off that buff/ reject if they're RPing or something. Perhaps add a negative version to opposite or losing faction if that is fair.