Steve Ballmer announced on Aug. 23, 2013 he would retire. The Board of Directors of Microsoft has since been searching for the next CEO. Today they announced Satya Nadella as the successor. Bill Gates will also become more active as Technology Advisor. John Thompson is elevated to Chairman of the Board of Directors.
Reference
Microsoft Press Release. (2014, February 4). Microsoft Board names Satya Nadella as CEO. Microsoft News Center. Retrieved February 4, 2014, from http://www.microsoft.com/en-us/news/press/2014/feb14/02-04newspr.aspx