A solid financial model for covering server costs, development, support and profit, preferable by subscriptions.
I'd personally be fine with $15 per month or more, with options to buy and gift non-recurring day, week or month passes for casual players.
Micro transactions are fine for premium costumes, emotes and other stuff that don't give the player a direct advantage.
A guarantee to avoid "sun setting", and a fallback plan to how the game can live on in case of financial issues, loss of key persons etc.
More alternative animations in power customization.
Two yoga-based powersets, one for melee and one for support.
A "huge female" or other way to make bigger and more muscular female toons.
More enemies that might require an adapted strategy, like sappers.
Allow all powersets and pool powers with customizations in Mission Architect.
Easy in-game share of deeds in social media (like Champions Online).
Allow all RGB colors in costume creator.
Upgrade old "body paint" textures to look like clothing.