Update 2: Verizon has confirmed that it is in fact an update to Android 4.1.2, not Android 4.2, as the screenshot below now reflects.
Update: It sounds like this may be an Android 4.1.2 update, not Android 4.2. The build number JZO54M is, according to Google's own codename site, an Android 4.1.2 build (specifically, Android 4.1.2 R2.1). Sounds like Verizon done goofed. We've reached out for confirmation, but I'd be skeptical if the Verizon XOOM suddenly bunny-hopped from Android 4.0 to Android 4.2. Thanks, Generic User!
Do you still have a Verizon Motorola XOOM? That you'd still actually want to put on stock software? Well, for all three of you still reading, you're in luck: Verizon just announced the Android 4.2 update for its version of the XOOM. And Motorola did it all on its own, because the XOOM is no longer a supported AOSP device.
Aside from the Android 4.2 features you'd expect, Verizon has a few other changes in store. An improved keyboard, a revised settings menu, connectivity and stability enhancements for the modem, and a search option in the pre-loaded YouTube app (seriously, that wasn't there?).
You can expect the update to roll out in the next week or two.