It would be very useful to have a discussion area attached to each wiki page, similar to MediaWiki. Ideally this would be organized in the UI similar to MediaWiki, with a simple tab for "discussion" or similar. This allows easy, intuitive, and quick navigation and use.

The feature could be implemented either as specific forum-like discussion areas attached to each page, or as normal forum threads simply linked to a page and displayed in the "discussion" tab, that are created as soon as someone uses the Discussion function on a page (they would only be created upon first use so as to avoid cluttering the forum with threads). Perhaps controlling which category the threads appeared in would be useful, although simply putting them in a "wiki" category would be fine. It may also be interesting/useful to allow multiple forum threads to be associated with a wiki page, though the actual use cases for this may be few.

I leave it to the devs to say which is the best approach. I think the fact that this function is available in most othrr wikis speaks well for its value, so I hope it will be adopted. Granted that most other wikis do not have other forum functions to be used instead as Redmine does, but I think the tight linking and ease of use of this type of solution is key to its importance.