"Kevin from s60 blog has confirmed a new implementation in Nokia N82. The phone has already came with a different firmware update process, which will keep user setting, application and data in the memory after the upgrade.According to Kevin, Nokia N82 is the first model that support data preservation. Nokia N82 will soon be able to test it as the first Nokia N82 firmware is coming soon.
With that said, having your settings and installed applications still there after a firmware update makes for updating to the latest firmware much more convenient. This feature has not been discovered by you guys and gals because there hasn't been a firmware update available yet for N82 (don't worry the first N82 firmware update that improves the stability of key applications is in the pipeline and will be available soon). " via slashphone.com