Some applications and games from third-party developers might need to be installed again after updating the phone firmware.
I suggest you take a look at the extensive FAQ on the Nokia website. Download the Nokia PC Suite and backup all of the files on your phone To do that simply start the Nokia PC Suite application and click on the Backup button. This might take a while if you have lots of personal files like images or music stored on the phone. Download and install the Nokia Software Updater application which is used to update the firmware of the phone.
This means it is not really possible to determine the new features and improvements of the new firmware version.
The only information about firmware updates was that they will improve performance and functionality.
You are probably wondering why you should update the phone if everything is working as intended.