There are two updates, the firmware and the navigation database. Updating the navigation database will not update the firmware and will not add any features. The original firmware in mine from 07/09 was updated during service. The firmware update removed the ability to load trips from a USB stick and added teh ability to manually enter a trip with multiple stops. Other than that change I don't know of any new features. If you replace your TCU with a Commbox and get the NAV recoded you can run BMW Apps.
'09 128i - Black Sapphire Metallic\Coral Red\Glacier Silver\N51 DISA\6MT\Navigation\Premium\M-Sport\Heated seats\Xenon Headlights\iPod\Smartphone