Should I buy the Macbook Air '13 (2014 model)? Because everyday I read somewhere that a '12 Air with retina display is coming out, so this rumor stop me from buying the latest '13 Air. Maybe there isn't a huge difference between the two but I don't want to buy the current one if some weeks later the reitna Air will come out shortly after. Is this rumor realistic? Should I wait? When the new Macbook Air are usually introduced?