We heard from AT&T that today was the day for the long-awaited Galaxy Note 2 multi-window update, and it looks like the carrier has stuck to its word. Several users in our forums are finding OTA notifications on their devices -- while others have had success checking manually -- and reboot to find the new feature in working order. The download all together is 178MB, which is quite hefty, and keeps the Note 2 on Android 4.1.2 for the time being.
See the update hit your device yet? Head to the forums and let the other members know how it's working out.
Source: AT&T Galaxy Note 2 Forums; Thanks, Larry!