It seems a new big update is coming soon to Google Search. Article at WSJ
Under the shift, people who search for "Lake Tahoe" will see key "attributes" that the search engine knows about the lake, such as its location, altitude, average temperature or salt content. In contrast, those who search for "Lake Tahoe" today would get only links to the lake's visitor bureau website, its dedicated page on Wikipedia.com, and a link to a relevant map.
For a more complex question such as, "What are the 10 largest lakes in California?" Google might provide the answer instead of just links to other sites.So if you have sites based on facts like lakes, mobile phones or others that can be easily categorized prepare yourself because you can lose a lot of traffic.Google also hopes the change to semantic search will entice some people to stay longer on the search site, said people briefed on the plans, amid competition with social networking sites like Facebook and Twitter Inc. that are claiming more Internet users' time.