I have a lot of time for Jeff Atwood and I suspect there is a lot of useful "outside the box" thinking in Discourse.
However I also think (based on a very brief look) that it addresses different problems from the success that this forum "suffers" from.
The problem here is that questions get lost in the jungle before the person who really knows the answer sees them. If anything, Discourse would seem to make it easier to create an even thicker jungle. In my opinion Stackoverflow with tags and votes is a better model.
...R