Microsoft announced a "minor release" to Windows Live Essentials 2011, indicating that it includes numerous updates to all of the programs in the Windows Live Essential package (Windows Live Messenger, Mail, Photo Gallery, Movie Maker, Family Safety, Writer, and Mesh.
The only indication of changes to Windows Live Essentials is that the release contains "critical fixes" and in time the update will be required for all eligible users. (Windows Live Essentials 2011 is not compatible with Windows XP.) So, don't expect any feature enhancements.
The update is available for download at the Windows Live Essentials website if you want to get the update now rather than waiting for it to hit Windows Update.