Nikon has released the Distortion control data upgrade for D90 and D5000 (I am an owner of Nikon D90).
The Distortion Control Data firmware upgrade is available for Nikon D90 and D5000 cameras only. This is used to correct barrel and pincushion distortion during shooting and editing. This may be loaded into cameras that support distortion control.
Has anyone upgraded his/here camera by using this firmware? Is it a critical "bug"? Has somebody seen any difference before and after?
Other updates we can see here.