This is actually pretty cool, and could be the one killer feature that would make me swap to IntenseDebate. As you probably know, IntenseDebate is a hosted comment manager for your site, just like Disqus.
And now they’ve added plugin support, with a bunch of them available already. Like instant YouTube embedding and Seesmic video commenting support. Check out the launch post, the ReadWriteWeb coverage, Techmeme coverage, and the intro video below: