From Encarta website:
On October 31, 2009, MSN® Encarta® Web sites worldwide will be discontinued, with the exception of Encarta Japan, which will be discontinued on December 31, 2009. Additionally, Microsoft will cease to sell Microsoft Student and Encarta Premium software products worldwide by June 2009. We understand that Encarta users may have questions regarding this announcement so we have prepared this list of questions and answers below. Please keep reading if you would like more information about these changes to Encarta.
See also the “obituary” penned by Noam Cohen, Microsoft Encarta Dies After Long Battle With Wikipedia, New York Times, March 30, 2009 and the comments generated by this post.