Nokia Belle, the successor to Symbian Anna and the first version of the OS to ditch the Symbian name, is now ready for download to older devices at Nokia's site. Belle includes six homescreens instead of three, an updated UI, new Nokia maps, and a new status bar, among other things. It's too large to send OTA, so you'll need to install Nokia Suite on your computer and then push the update to the phone via USB.
The Belle update currently applies to C6-01, C7, E6, E7, N8, X7 and Nokia Oro phones; a version for the Nokia 500 is coming in a few weeks. Although we're sure Symbian phone owners will appreciate the update, Nokia still hasn't said whether it will be planning further versions of the OS. There are still a lot of Symbian phones out there, but Nokia's focus on Windows Phone doesn't bode too well for the people who own them. For now, though, you can check to see if the Belle update is available in your country with this map.