To start with auto updates are disabled when 2.2 is released and you have to update manually by downloading the zip from your account area. With this simple file edit you can let WP do the update as if auto updates were enabled.
!Caution! Please make sure you do a backup before ANY WP plugin updates
Step One
Edit the following file, change the version in this file to 2.2-beta This will trigger the beta to stable 2.2 update.