Today a few owners have told ToT they are getting the Android 3.1 upgrade earlier than Google said they would. The build is virtually identical to the one reaching 3G Xooms on Verizon and brings movie rentals, USB peripheral support, resizable widgets and a deeper multitasking interface. Early adopters have also found it noticeably faster.
The update is still due to be pushed out gradually for those waiting for an automatic delivery. A chance exists that a manual check will speed up the upgrade process, but no Xoom Wi-Fi owners have reported it working so far to us here at ToT
