If you're a Motorola Xoom WiFi owner who's been waiting for Motorola to roll out their previously mentioned software update, you'll want to check your emails. Emails being sent out to registered users of the Motorola feedback network confirm the update will be arriving today at some point:
Thanks for signing up for the Motorola U.S. Wi-Fi Xoom software test. We had a very enthusiastic response to our call for participation, so we expect a good turnout. The software should be pushed to your phone later today. Thanks so much for your participation! We really appreciate your time and insights. We’ll start the push soon so please start your visit to the private community here. You’ll find additional important information in the Welcome message as soon as you sign in.
At this point, there isn't any confirmation of it being Android 4.1 Jelly Bean but all signs point towards that, especially now that Google has begun the push of Jelly Bean to the Nexus S variants out there. For those of you not on the Motorola feedback network, you'll have to hold out a bit longer to see this update.