Yesterday Motorola officially announced that Android 3.1 would be hitting Verizon 3G XOOMs first, then WiFi and other variants "in the next several weeks." I'm not really sure how Motorola defines "several weeks," but it appears to be a little bit different than the rest of the world, as we're starting to see reports pop up all over the net that suggest the update may already be underway.
That's about as deep as the details go for now, but if you get the update on your XOOM, make sure to let us know!
Update: It doesn't get much more official than this:
It's about time a manufacturer started over-delivering for a change. That's what we like to see, Moto!