If you go and check for updates to your iPhone, you will find that there are updates for the carrier settings on the phone.
According to Apple’s knowledge base, the following has been update:
iTunes 7.7 and later has the ability to update the carrier specific settings on iPhone with iPhone 2.0 software or later. Carrier settings updates are small files (about 10k) that are downloaded from iTunes to be installed on your iPhone. The carrier settings can include updates to the default APN (how iPhone accesses the carrier’s cellular data network), special dialing codes at Settings > Phone > [Carrier] Services, default settings for Stocks, Maps, Weather, and other items.
According to TUAW, this is what is really being updated:
Logo replacements, apparently, for AT&T’s upcoming MicroCell service (at the time of this writing, the page is in maintenance mode). 2 images, light and dark versions of the image on the left (courtesy of MobileCrunch). Commenters atThe iPhone Blog also confirm the revised connectivity image. Our own commenters note that Apple has added settings for the Mobily network (Saudi Arabia) and Etisalat (United Arab Emirates) in this update as well, which adds weight to the expected 2/15 launch of the iPhone in those countries.