...SearchWiki, a way for you to customize search by re-ranking, deleting, adding, and commenting on search results. With just a single click you can move the results you like to the top or add a new site... The changes you make only affect your own searches. But SearchWiki also is a great way to share your insights with other searchers. You can see how the community has collectively edited the search results by clicking on the "See all notes for this SearchWiki" link.This has been in testing for awhile. See my previous post on Google's Wiki of Search and Eric Schmidt's notes from 2006.
I think getting users more involved is a good idea, especially when you have an audience as big as Google. However, I'm skeptical about the current system's utility. For example, it is disconnected from Google's related products, such as Google Notebook and Google Bookmarks. It doesn't allow me to incorporate my social network. I don't think that most people have a compelling desire to edit or comment on their own search results. A few common queries may get edits, but what about the long tail of search? That said, maybe I'll go change the ranking for a few vanity searches anyway ;-).
SE Land also has informative coverage.