I think it's important to mention that anyone who decides to upgrade their existing MM account to iCloud before next June read this from the Apple FAQ,
" "What happens to the other sync services I use for my Mac?"
Syncing of Mac Dashboard widgets, keychains, Dock items, and System Preferences will not be part of iCloud, but will continue to be available for you to use until you move to iCloud. After you move to iCloud or after June 30, 2012, whichever comes first, those sync services will no longer be available. Other MobileMe services that are not transitioning to iCloud (iWeb publishing, Gallery, and iDisk) will continue to be available through June 30, 2012, even after you move to iCloud."
I am holding off until next June until I decide what 3rd party services will work/replace my iDisk and Gallery, and syncing services system wide.