Everything carrier update
Welcome to iOS, Verizon iPhone users -- Apple is sending a carrier update your way! We don't know what it does yet but typically carrier update files control carrier-specific features
The AT&T Carrier Update (v5.5), required to enable MMS on the iPhone is now live and can be installed via iTunes. Just plug in your iPhone and if it doesn't
UPDATED: Comparing the before and after states of carrier.plist, iambored8907 reports in the comments that the update added PNG graphics for AT&T's new MicroCell (Femtocell) service:
AllowPrefixMatching CarrierName AT&T
