Widgetslab has a very thorough post up about the intensifying competition in the blog comments space between companies like Disqus, JS-Kit, and Intense Debate.
Widgetslab covers a number of areas in which these companies are trying to differentiate themselves. Profile, seo-ability, and synchronization with a native blog commenting system (like Typepad or Wordpress) are three of the primary battlegrounds.
I believe that the blog commenting space has some serious network effects - the more blogs that adopt a certain, distributed blog comment provider, the more pressure there is on other blogs to switch over as not to silo themselves (and their commenters). I recently left a long comment on TechCrunch and found myself pissed off that the comment would now just slide down the river to obscurity, with no easy way for me to archive it. Until TechCrunch adopts a networked commenting system, I will be unlikely to post more comments there.
Because of these network effects, we may very well see a winner take all scenario emerge at some point in this space. For this reason, today's skirmishes between the blog commenting contenders are worth following.

