Today we announced Office 365, which will bring together the Cloud versions of Exchange, Sharepoint, and Lync (currently sold as the Business Productivity Online Suite, or BPOS), with our Microsoft Office products, both on the desktop and in the Coud.  Couple of links:

Press release: http://www.microsoft.com/presspass/features/2010/oct10/10-19Office365.mspx

Office 365 Website: http://office365.microsoft.com

Gartner's first take: http://www.gartner.com/DisplayDocument?ref=clientFriendlyUrl&id=1454015

Beta signup: http://office365.microsoft.com/en-US/office365-beta.aspx