I still believes that the rumored 12-inch iPad Pro and the rumored 12-inch Macbook Air is the same device. Of course will Apple release new MacBook Air's with even thinner design, running on Intel Broadwell chips and so on, but that is not this device. I believe the rumored 12-inch device is the next step in Apple's evolution. It will be an iPad, running iOS with a keyboard/touchpad solution we never seen before.
Apple's 12-inch MacBook Air and the Apple Watch are expected to enter mass production in 2015 as the company's supply partners have accelerated component production for both products