Commenting 2.0 service Disqus has landed Mashable as a client, with a new offering that incorporates social media tracking for the first time.

Mashable adds exposure to 2.4 million readers on 5.2 million page views to the Disqus network (stats per Quantcast.) Disqus hasn’t been as aggressive as its competitors in acquiring site signups, so this is a much welcomed boost.

Mashable’s rollout of Disqus though isn’t a standard install. Disqus has teamed up with closed beta conversation tracker UberVU to deliver social media reactions into the comment area.

According to Disqus:

If Mashable’s posts are discussed on Twitter or Digg, those tweets and comments will appear in their Disqus powered comment system. Other supported services include Flickr, FriendFeed, YouTube, and many more.

Pete Cashmore writes on Mashable that the system isn’t perfect yet, and that ideally it will eventually include the ability to post back to these services.