Hello,
I think that quite a few people here have done extensive research on this subject and their ideas present a quite contrasting picture. I would definitely talk with Daniel Brandt about this. You might wish to send him a private message, for a "head's up".
This article on Wikitruth , although dealing with section 2257 (obscene images) rather than section 230, provides a very amusing study of why Wikipedia could not probably claim to be a common carrier, by their own admission. This could be important in building the case that their claims of being a service provider are not valid. They will deny this, of course, but given their recent, completely arbitrary and possible illegal plan to change licenses from the GFDL to a CC license, the fact that they are asserting that they do have this right to impose a license which tend to suggest to me a pubisher's role; A "service provider" does not assert any control over these sort fo issues, other than to avoid liability.
PS I would suggest to mods that this could be more visible in the main forum, as it's probably not about a specific WP article.