I have an iPad Air and bought the Air 2 recently. The Air 2 model fits in the Air case, however, the cover holes do not line up for the camera, or mic placements on the Air 2. The fit is OK, but the magnetic lid/flap has to drop down into the rear shell now, instead of being flush with the corners. This can prevent the magnetic switch from functioning. It gives some protection, but I bought a case on Amazon for $12 with free Prime shipping. I got it Friday and really like it so far.
Swees iPad Air 2 Case
Good fit, light weight and thin. Might not be as much protection as some want or need, but plenty for me. The back has the same carbon fiber pattern, and is easy to grip, not slippery like some of the plain backed ones I've seen.
I got the red, leather grain version for my wife, and she's very happy with it also.