Not really - it's mainly intended to blog you mapping activity.

The mailing list at http://lists.openstreetmap.org/listinfo/talk is the main forum for discussion (it's a mailing list not an online forum). There are various other lists at http://lists.openstreetmap.org/ for specific topics/locations.

There is also

http://forum.openstreetmap.org/

Oh, and you can also edit the wiki (wiki.openstreetmap.org) for more permanent things. You have to register separately for that.

... and I can only repeat my wish to the OSM webmasters:

Please add a link to the forum on the main page of www.openstreetmap.org.

Why not?