I think there's something I'm not getting about coComment. I've gotten it working via a Greasemonkey script, so I see my comments starting to get tracked. But, I'm not seeing others' comments. Well, except for other coComment users, that is. Is that the deal? Everyone needs to opt in?
I've noticed this as well, it seems the service is just for keeping track of where you left comments, not really to follow up on the discussion.
I've also found it's a real pain to find the link of the original article, there's only one link and it's a very small image, like 8x8.
For the moment, coComment can indeed only track coComments in a thread. It's an issue we beta testers raised as soon as we got hold of it. It's not a feature. I mean, it's not done on purpose to force people to sign up -- it's more of a technical problem: not all blog platforms provide comment feeds. And if they do, how often will you scrape them?
As far as I know, the coComment developers are aware of the problem and thinking out a solution. If you make yourself heard in the forum it might encourage them to put even more energy into solving it. You might also want to check out the development priorities post on the TeamBlog.
Use http://co.mments.com instead. It doesn't suck.
Hmm, interesting! I wonder how co.mments.com tracks the comments in the page? I'd been thinking idly on and off how to make a service like this over the past year or so, and as Stephanie points out, that was one of the things that had been keeping me from tipping over the lazy threshold...