'Social Networking' the 3rd Leg of Ballmer's Online Gambit

A while back Steve Ballmer was taking about Facebook being a fad. Microsoft, of course ultimately invested an extraordinary 15 Billion in them which should signal their commitment to the social networking space, but I noticed the following statement from his email to the troops after walking away from this Micro-Yahoo deal that cements it as a priority in their online strategy:

Ultimately, our goal is to build the industry-leading business in search, online advertising, media, and social networking.

So naturally I think back to the Microsoft/Digg rumors....While Digg is primarily a "social news" site it has social networking value to be sure. I wonder if Microsoft will still be considering Digg if they really walk away or force Yahoo to commit hari kari.