Does this mean they'll use their own search engine at last?
It's about time. The current effort isn't much more than a wrapper a script kiddie could throw up in half an hour with a random background image to attempt to fool those with single digit IQ's, such as WP7 users. Don't believe it? Here we go: http://googleblog.blogspot.com/2011/02/microsofts-bing-uses-google-search.html