I don't agree that CoH is worth saving, but I think a new online - or at least co-op - superhero game done right would go over exceedingly well. I'm acutally surprised there haven't been more attempts given the popularity of comic books/movies and games like Bats AA/AC these days. The market is definitely there for it.
“There is no such thing as a weird human being. It’s just that some people require more understanding than others.” - Tom Robbins