Although Motorola has never come forward to explain what took so long for them to get the 4G LTE upgrade for the Motorola Xoom, they recently announced that it will become available in September. That's quite a bit of time between when they promised it would come out, in May. But, whatever the delay, the company began sending emails out to owners letting them know that they could expect it sometime in September. Here's a quote from the BGR article with a few more details,We will let you know as soon as a more concrete date becomes available.Applying the 4G LTE upgrade requires that a new modem replace the old one in the XOOM, and Motorola will need customers to ship their tablets out for up to a week in order to have the upgrade applied. The process will be free of charge for XOOM owners.
Source: AndroidTablets.net and XoomForums.com via BGR