Google has been providing personalized search results for years, and changed its tactics often. Their latest application will replace SearchWiki in favor of adding a "star" to a search result you want to see up top of your search results in the future.
According to Google, it’s a new search feature that is rolling out now, but should be available to everyone in the next few days, . When it becomes available, any result you click to star is added to your Google Bookmarks, Google Toolbar, and any searches you do in and around that topic in the future. So if you star your local favorite coffee spot, expect to see it in a mini-box up top when you search for "coffee" in the future. SearchWiki results will stick around for those with Google accounts.
How will this affect SEO? It’s too early to tell but I bet google will track how many people are starring a website and use that weight to rank that site better. It will give the site more importance over others if more people want to see it at the top of their results. I also wonder how SEO companies will take advantage of this tool.