Hey, thanks for the link!
Yep, I'm primarily talking about the general aesthetic of it all. The whole design not only looks good but also makes the navigation of threads and their replies really easy.
Each thread is a box, and each reply in... each thread is a box inside that original box!
What I really like is how pages with quite a few comments load in a "collapsed" state. And that "collapsed state" looks cool!
If you want to see what I'm talking about, check out this page:
(and if you've visited it before, maybe clear your cookies to see all the comments collapsed.)
I've never seen anything like that before. I love it, and think it's genius.