Amazon is piloting ProductWikis, a single wiki page for each product with wikiwyg-like editing and revision history. Launched late last year, now you can view Most Edited Wikis and Last Edited Wikis in attempt to focus contributions and reverts. You are notified by email of changes to pages you contribute to, and I quickly got in an edit war with this guy. Also apparently, you can add links. You can create wiki "term" pages by linking to them from product pages, like this one.
I have no doubt that some form of this will complement that product pages of most e-commerce sites, whether hosted by the vendor or not. It's difficult to say whether this pilot will work or not, given the level of fragmented interests and how it is buried in the interface. But adding the basics for moderation and linking is a good step.
