You'll notice if you try to update your iPhone carrier settings using the final version of iTunes 8.2 the .ipcc files are greyed out. In order to re-enabled access to these files you will need to follow the simple steps below.
Click to launch Terminal from the dock or from the Applications:Utilities folder.
Enter the following command into the Terminal window:
defaults write com.apple.iTunes carrier-testing -bool TRUE
Connect your iPhone and click to launch iTunes from the dock
Select your iPhone from the list of devices on the left then hold down the Option key and click the Check for Updates button.
Notice you can now select your .ipcc file as it is not greyed out.