Don Ferguson, formerly IBM Software Group's Chief Architect, now works for Microsoft. His IBM blog, which is still available at the moment (if the link becomes stale, try the Google cache), has changed employers and now works for Microsoft. Quoting from his IBM bio,
Donald Ferguson is one of 53 IBM Fellows (IBM's highest technical position) in IBM's 200,000 employee technical team. Don is also the Chief Architect for IBM Software Group. Don chairs the SWG Architecture Board, which oversees the architecture and integration of WebSphere, DB2, Lotus, Tivoli and Rational products. Don was the original Chief Architect for the WebSphere family of products. Don joined IBM Research in 1985.
Now, Don has become a Microsoft Fellow (one of fifteen); on the Microsoft site, his bio starts like this:
Dr. Donald Ferguson is a Microsoft Technical Fellow in Platforms and Strategy, in the Office of the CTO. Don focuses on both the evolutionary and revolutionary role of information technology in business. Understanding the trends, architecting and piloting the implications for existing and new products and evangelizing Microsoft’s vision are the key aspects of Don’s job.
In any case, a very interesting career move. Sanjiva Weerawarana, who worked for Don while still at IBM, predicts:
This is a huge loss for IBM and a huge gain for Microsoft. I'm sure Don will enjoy, no love, the challenges of being in an entirely different new world and will have major impact on Microsoft!