Motorola didn't say when pre-orders for the WiFi-only Xoom would be available when it finally announced the device yesterday, but some retailers have now stepped in and answered that question. You can currently pre-order the device from Amazon, Staples and Costco, with other participating retailers presumably set to follow shortly. In case you missed the news, the Xoom WiFi will run you $599 for the one and only 32GB version, and it will be available on March 27th. Staples will apparently be shipping them out on March 25th to ensure you get it on launch day (if you pre-order before March 23rd), while
