Well, the black hats are going to have a field day when they read what Marissa Mayer has in store for SearchWiki. From TechCrunch, with my emphasis added:
Mayer also talked about Google’s use of user data created by actions on Wiki search to improve search results on Google in general. For now that data is not being used to change overall search results, she said. But in the future it’s likely Google will use the data to at least make obvious changes. An example is if “thousands of people” were to knock a search result off a search page, they’d be likely to make a change.
Who here doesn’t think that would be exploited?
PS. Mayer also reveals that Google might introduce an "off" switch for SearchWiki–if, like me, you hate seeing the clutter in your search results.