From Niall Kennedy's blog post entitled Facebook enters the workplace we learn

Popular social networking site Facebook is moving beyond schools and into the workplace. A new version of thesite went live this morning allowing new registrations on corporatee-mail addresses. I was able to signup using my Microsoft address andcompleted my profile.

From the press release Microsoft Spins Out a Wallop we learn

Microsoft Corp. today announced the spinout of a new social networking technology, developed by Microsoft Research, to create a new Silicon Valley startup, Wallop Inc. Wallop, whose aim is to deliver the next generation of social computing, is led by experienced entrepreneur and CEO Karl Jacob, with 30-year veteran Bay Partners providing Series A financing.
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Wallop Advances Social Networking
Launching later this year, Wallop solves the problems plaguing current social networking technologies and will introduce an entirely new way for consumers to express their individuality online. For example, today’s social networks have difficulty enabling people to interact in a way similar to the way they would in the real world. Wallop tapped legendary Frog Design Inc. to conceive a next-generation user interface enabling people to express themselves like never before. In addition, Wallop departs from the friend-of-a-friend model common in all social networks today and the root of many of their problems. Instead, Wallop developed a unique set of algorithms that respond to social interactions to automatically build and maintain a person’s social network.

Interesting moves in the world of Social Networking. Facebook moving into the competition with LinkedIn is unsurprising. Microsoft spinning of Wallop so that it may eventually be a competitor of MSN Spaces was not. I guess I'm not as plugged in as I thought at work.