Facebook has just announced its own internal search engine mining 1 billion people and 1 trillion connections. They are calling it Graph Search. For results outside of FaceBook, Bing is being used in conjunction with a new partnership with Microsoft. It will also pull results from Yelp.

Apparently you can search on all Facebook data held that is not marked private and then receive information from Bing.

This is clearly just the beginning of their search software. I wonder if this is the start of a full frontal march on Google Search? With Bing & Yelp integration this seems very likely.