Nokia announced their plans for Symbian

The next Symbian versions after Anna and Belle are going to be called Carla and Donna as Nokia announced at the Nokia Developer Day conference in Mexico. Symbian Carla is going to be released in late 2012 and will be supported by devices with processors running at 1gHz or more. With it users will receive a new browser, new widgets, Dolby Surround support and more. This means that current Symbian devices such as the N8, C6-01, C7, E7, E6 and X7-00 probably won’t receive an update to Carla.

Donna is expected to be released about one year later and is going to run on dual-core devices. This means that it’s going to come with mid-range devices ( dual-core is currently being replaced by quad- and quint-core) which isn’t quite bad, knowing how good Nokia is at optimizing software to run on mediocre devices. Nokia had also announced that they’re going to stop developing Symbian in about 2016, so these updates will probably be the last ones.