Matt, a Motorola forums manager, made a statement in one of the threads saying the Motorola Xoom would get updated to Android 4.0. In fact, Droid-Life says the Gmail app from Google's upcoming OS already works on the tablet. We can't say we're surprised to hear that the Xoom will get Ice Cream Sandwich — Google and Motorola are pretty good friends right now. You can read Matt's full statement below.
I don't know anything about if it will be first or not -- have no insight into how other manufacturers do updates -- but Xoom will get ICS. I just don't have any timing to share. - Matt
Considering Nexus phones tend to get the latest software relatively quickly, and Android 4.0 updates are expected as early as December, we'd guess the Xoom will get Ice Cream Sandwich sooner rather than later.