As most printer/scanners now connect via USB, the cable is most likely NOT going to be the big issue, The problem is going to be that there are no drivers available for the Xoom to be able to send/receive even though the physical cable connection is in place.
I have had success printing via Cloud Print (free in AndroidMarket) to printers connected (even via WiFi) to computers running Google Chrome, and, in the case of a WiFi connected HP all-in-one, using PrintBot and HP ePrint to print (only). Scanner software for Xoom/Android may not yet exist.