In the same company earnings call that the Atrix and Bionic release dates were revealed, Motorola CEO, Sanjay Jha, announced that the 3G-enabled Xoom will arrive at "the end of February." However, he then followed up to his comments in the Q&A portion of the call and stated that the release may slip to March.
Although a slip just a few weeks isn't too dramatic, it means that the company is not as ready as they would like us to think. Even though it's slipping, Jha states that he is very confident that they'll make their timeline. We can only hope.