I'm looking for a product that i'm not sure exists.

Here's what I want to do:
~ I want to have multiple authors contribute articles to my site that are organized and cataloged by subject by date, AND
~ From these articles, I want people to be able to reply to the article (kinda like comments at the end of a blog) and have a discussion about the ideas in the article or fraction off into other discussions.
~ But the trick is, I want ANYONE (not necessarily staff authors) to be able to precipitate a conversation by posting their thoughts/opinion (like a forum).

I *could* just have the authors write their articles in the forum but I prefer the content to be cataloged more like a news site/blog (allowing for better mark-up, photos, diagrams, etc.)

I could also just implement all these different components (Blog/CMS/Forum) but I'm hoping that there's a way to do all this already. (I think Sitepoint.com is the closest to what i'm looking for but their forum isn't connected to the content articles.)

Anyone have any ideas??

Joseph