Search engines have been doing this for about 6 months. The basic concept is simple. Your site is based on themes anyway. Many sites have more than one theme. The search engine takes a look at the over all concept of the site. If you have strong themes, your site ranks higher.
>Is it true that most of the major search engines are employing a new way of ranking sites?...
>They crawl your whole site and decide on what the dominant theme is regardless of the intent of individual pages and subsections?
>Sounds problematic on many levels.
>Have you guys heard of this?