This morning there's an article over at news.mmosite.com going over the finer details about why CoH should be worried.

Summary: In my previous article, I ruffled some feathers by saying that City of Heroes had nothing to worry about concerning the impending release of Champions Online, its first competitor in the superhero MMO market. Maybe "nothing to worry about" is a little too strong. There are lots of valid reasons for the developers of City of Heroes to keep an eye on Champions Online, and I have no doubt Champions Online will do quite well for itself. While I don't believe that City of Heroes will just shrivel up and die in the wake of Champions Online's release, what follows are some of the reasons I think Champions Online could steal much of CoH's thunder.