Quills seams to be a very valid Blog. Maybe it could also be used as news publishing tool. The advantage of Quills over sdot_news is the possibility, to assign more than one topic to a single entry. On another plone site I installed Ploneboard, a forum. From a first look it seams valid, too. But at the end we decided to stick with a mailing list and a wiki, because it's much easier to motivate communication on mailinglists.