Nokia announced the PureView 808 and said that it will be running on Nokia Belle OS. While there were a number of demonstration videos seen at the MWC of the device, the platform seemed to have some new features.
So this brings down to the conclusion, that Belle will be receiving an FP1 (Feature Pack) update in the near future. Rumours are also suggesting that this new FP1 update will be the new Nokia Carla update as earlier reports said that Carla will be v112.
There is also confirmation that the Nokia 603, 700 and 701 will be receiving the FP1 update, which means that these smartphones might be getting the Carla update as well. Some of the features which you can expect in the upcoming Belle update will include a whole new multitasking UI, somewhat like WP, new browser version 8.2, newer widgets, updated camera app and Nokia Maps App and some more bug fixes.