Mathias-
when I read your mail, it reminded me on the typical reactions of some people who did not know wikipedia and heard about writing an encylopedia bye allowing anyone to post :)
Actually, there's a key difference. We have a "no original research" requirement on Wikipedia for exactly the reason that we can't rely on original research by anonymous contributors (also, because it goes beyond the scope of an encyclopedia).
Controversial information in Wikipedia has to backed up with sources and citations. Anyone can provide a citation, it doesn't matter whether they are anonymous as long as the source is obtainable and can be verified by others.
For a real news service, original research is of course essential, and for original research to be credible, there have to be reputation and accountability attached to it. One of the worst mistakes we can make is to treat wiki as a dogma. Wikis should be the basis of all Wikimedia projects, but the exact parameters in terms of policy and technology should be varied depending on the individual project needs.
Regards,
Erik