A few days ago, Motorola pushed out a special soak test of the ICS update to a number of Wi-Fi XOOM owners in the U.S. Apparently, no serious issues were found by the company's engineers, as the very same Android 4.0.3 update (IML77) is now rolling out to everyone. Well, everyone in the U.S. with a Wi-Fi XOOM that is. This makes the XOOM the 2nd mainstream tablet device to officially receive ICS, losing out only to the Transformer Prime that beat it to the punch by only a couple of days.
Head over to Settings > About > System Updates to see if the 81.9MB update is available on your XOOM, let it do its thing, and enjoy the greatest version of Android Google has ever created.