Luis Villa, from WMF, asks if there is a list that wants to try Discourse:
https://lists.wikimedia.org/pipermail/wikimedia-l/2016-January/081244.html

Discourse is a (great) software for discussion, and it could be very useful for giving order to the many mailing lists that we have in the Wikimedia world.
This list is active but not too much, so I'm asking you if we want to propose as guinea pigs :-)

Many great open source projects use Discourse, so we are far from being pioneers, and from what I've seen we could really benefit from the many features the software has.
Just look it yourselves:
discourse.org

Aubrey