In less than 4 hours of being released to the general public, the Motorola XOOM has been rooted. Along with full root access, a custom clockwork recovery has also been successfully installed on the device. The credit of all this hard work goes to Koush the developer of ROM Manager.
ROM Manager is one of the most popular ROM managing apps available for the Android OS. According to koush, rooting the XOOM was easy since the tablet is Google experience device, and thus ships with fastboot support (limited though!).
The steps to root the Motorola XOOM can be found here. Koush has not made the custom recovery available to the public since the SD card slot on the XOOM does not work.
He will release the custom recovery once Google releases an update which will enable the microSD card slot, or once the developers somehow manage to get it working! Once the microSD card slot gets working, koush will update his app ROM Manager to support the tablet as well.