I want to see the fulfillment of our roles as Incarnates. Finish up the system
The Battalion
Some sort of Arch-nemesis system. Let us create a villain that will grow with us, periodically crossing our path in missions.
A continuation of the official, planned storyline from before the game was shut down. Tweak it to give us some surprises, but otherwise continue what was planned.
Creative ways to use powers: a super strength character can lift a pile of debris blocking our path, a flying character can rescue a cat from a tree, ice and water powers putting out flames in missions, etc.
More face options
Bare feet that don't look like boots with toes drawn on
IF you add new ATs, please invest as much time as possible to actually balance them properly
Moon Zone
New Mastermind pets
And while this probably won't be what other people want, I would much rather pass on new archetypes in favour of reworking the power pools.
Let us use pools to round out our characters, instead of trying to create new ATs like "ranged melee" or tank controllers, or whatever.
If you want to play a character as tough as a tank, but with ranged attacks, play a Tanker and invest in a ranged attack power pool.
This would be much easier to balance, in my opinion.