Nokia will be somewhat late in rolling out Symbian Belle to phones that didn't already have it. A statement from the company confirmed to All About Symbian that the 500, C6-01, C7, E7, N8, Oro, and the X7 will get the OS update in early 2012. It didn't explain the months-long gap between then and devices already shipping with Belle, like the 603, 700, and 701.
The OS is a sweeping change to Nokia's outgoing smartphone platform that provides lock screen notifications, a new taskbar, more visual multitasking, and more complex widgets. Phones that have NFC get more direct software integration for reading tags and sending data.
Belle won't necessarily be the last update to Symbian on smartphones, but it was the last to have been made available before Nokia's switch to Windows Phone as its foundation. Nokia is gradually ramping down Symbian smartphones over the course of the next one to two years.