Yesterday's release of SearchWiki is being highly discussed in the SEO world, and in good reason, as thousands if not tens of thousands of people make a living gaming the SEO system to make their articles and products show up in the top spot for certain search results.
I think its important to note that for right now, individual's votes don't affect anyone else's searches. Sure, Google will be storing this information, and chances are, they may ATTEMPT to include this voting behavior on general web results eventually, but we're a ways off from that point.
For the time being, if you search for a website regularly, you can make sure that that website will always show up as the top result for that query. You no longer need to bookmark a page. You can just vote it up specific to a certain query.
This gives users one more reason to go to Google in the first place. Win Win.