Kinda late to the party here, but, like many others have expressed, I'd like more content.
Specifically:
Story Content: It doesn't have to be filled with cutscenes and crazy things like they were doing towards the end of CoH's life, but one of the biggest issues right now is running out of new content to run. I'd like to see places like Perez Park, Boomtown and other forgotten zones get their own story arc contacts.
Raid content: We need more variety.
Other things:
Finishing the Incarnate system: The endgame system is unfinished. In turn that means its really unsatisfying since you know you're playing an unfinished character.
More costume options: More costumes are always great. I wouldn't even mind having to pay for costume packs if it ensured that the quality was high and the flow frequent.
Updating costumes: Some older costumes have rather low quality textures and some don't even mesh properly with other parts of their "set." It'd be nice to see some of the older parts get a lick of paint (provided they still basically look the same)