I took a look today since I'm buying a new MacBook Air. And sure enough they have them!
http://kbcovers.com/reason-keyboard-cover/
These are silicone covers. I've always liked the idea of these over stickers. And of course, as a laptop user, buying a separate keyboard that is printed upon isn't the best option. And especially great for those who run different pieces of software and want to swap them out. $29.95 though. But there are some promo codes out there.
I feel like there are a few more things they might have been able to fit on there. And although I don't need it, nice to see the Rack flip labeled
Here's a video showcasing the cover for Illustrator: