Microsoft promo: buy a Surface RT, get a free keyboard cover (updated)

There's no question that the Surface RT comes into its own with a keyboard cover; we can't imagine using the tablet unadorned. Microsoft can't, either, as it's launching a promo that gives the covers away. Americans and Canadians who buy the Windows RT slate between now and the end of June can get either the Touch Cover or the Type Cover for free, no matter which color they fancy. Surface Pro customers are out of luck, but it's hard to dispute the value for prospective Surface RT owners -- the deal amounts to at least a $100 discount on the touch PC's real-world price.

Update: To be clear, this promo has been running in other countries; it's just now debuting in North America, however.