It has some interesting new ideas, but there's also some clutter and quite unintuitive things. Maybe I'm too used to traditional forums like phpBB and the like, but have a look at this example post:

http://try.discourse.org/t/video-games-for-pre-teens/101

1. Why does the initial question highlight and fade out? I find this distracting. It's clear that the thread starter is on top.

2. The information right below the initial post is...weird. What does it have to do with the thread?

3. "2 replies below" gets outright confusing. Why? Because you can open this dropdown-box and find posts that are listed on the same page anyways. Furthermore, it is not consistent, because the first "direct" reply is in this dropdown-box, but further down, it is NOT marked as a direct reply. The other "direct" reply however is marked as such (5th post).

4. Why does the bar right under a post have a mouseover-effect but doesn't do anything?

5. Very interesting: The collection of links that were posted throughout the entire thread. Good idea!

6. Also interesting: The participants of that thread. However, I can't see their names if I mouse-over their pictures.

Conclusion: Looks promising, but for now it has a cluttered feel to it. So, I'm not sure if I'd actually use it as a discussion forum on my website.