I think it would be helpful to have a serverside wiki in addition to the threaded discussions.
The wiki concept (see the c2 wiki) for the original wiki) is much nicer for catagorized discussions. They are a bit easier to read and also are easier to get into.
They aren't quite as good for asking questions so I would keep the threaded discussion lists, too.
Thank you for your suggestion. Our patterns section is very similar to a wiki page. You can post a pattern, which is similar to adding a page on the wiki.
Once you have posted a pattern that thread can be added to sequentially by replying to messages, almost exactly the same as appending sections to a wiki page.
I do see the value in having wiki functionality (you can add the equivalent of new forums, whereas here you can't), but in doing so we will not be able to integrate wiki pages with some upcoming features: having posts emailed to you, digest of recent posts, as well as some of our current features (having recent patterns / hot threads on the home page, etc), so having a wiki could create significant integration problems.
One thing I would like the Wiki for is to have a "developers free for all" section, that could be unmoderated and could basically grow in any direction developers would like.