Nothing like a little software update to get the weekend started right right? Just days after Samsung shipped the first consumer units of its Galaxy Tab 10.1 (you can find our review here), the Android 3.1 update that first struck Motorola's Xoom is now gracing the Limited Edition models that were handed out at Google I/O 2011. We've confirmed here at Engadget HQ that the update is indeed percolating, with American