Bing has posted a blog showing webmaster the thinking behind its search algo, except from if follows:
In June 2009, we launched Bing (www.bing.com) with the aspiration of building a search engine that better understands what people have in their mind while searching so that we can help them get their tasks accomplished faster and more easily. The core to a great search engine has been and will always remain the same: delivering comprehensive, relevant and unbiased results that people can trust. We use thousands of signals from queries to documents and user feedback to determine the best search results and in turn make hundreds of improvements to our features every year, from small tweaks to core algorithm updates. As the web grows, we continue to take advantage of the collective wisdom from social, real-time, geospatial and contextual signals to further improve the search quality of Bing.

you can read the full blog here: http://www.bing.com/community/site_b...-insights.aspx