Some of the badges do give perm boosts which is awesome.
What I'm thinking is something along the lines of POE (Path of Exile) or WoW (World of Warcraft), POE makes you grind out challenges which gives you Micro Transaction Gear, allowing you to change the look of your toon with special effect and even skill effects. Or with WoW most of my friends who play it enjoy grinding for the new mounts and look forward to it, so maybe adding in something that gives your travel powers a new look.
Personally I would really enjoy new seasons to CoH where this season quest lines and change things up, the world is now lost to the Rikiti they took over Atlas Park for the season and we need to beat them back, and completing these quest and helping out gets you new looks to show your participation. Or maybe the Lost built a underground city for a season (seasons normally lasting 3 months) and you have to stop them from using a bomb to destroy King's Row. Just something different and optional to participate it.
It doesn't just have to be "Kill 1000 Rikiti Monkey and now you get a Rikiti Monkey face skin" it can be more detailed and elaborate.
It's food for thought, and a new fresh idea to a game that seems to be stagnant. Or hell, make the ultimate season store line reward..... Save Atlas Park and you now unlock a new power set and level option from 50 to 60. Who know, but lets open the idea up for advancement to this game, and honestly the best way to keep fresh content is to break it up in seasons.