Just as Eric and I were having an involved conversation about where search is headed now that everybody's tagging stuff, Kevin Ryan comes out with a nice piece on iMediaConnection.com that will give you the skinny on where things are headed. If you think about it, the Google currency has been built in part on inbound links, a concept which has been mostly fair and mostly accurate. What's the next step, accuracy-wise? Tallying the classifications that people who actually use the content give to it, and determining relevance appropriately.
Fortunately, this keeps the concept of a Google bomb workable. Just get everyone to tag a pic of President Bush with a "jerkwad" tag.