As MacRumors notes, while it was already expected that the iPad Air 2 and iPad Mini would have a Touch ID fingerprint sensor, it seems from this new replica that there may well be other, previously unknown, features that have also been added to the Air 2.
Aside from the Touch ID home button, there are also some other clear differences to be seen from the first iPad Air, such as a new speaker grille with bigger holes on each side of the Lightning port, which differs from the smaller holes in double rows of the current iPad Air.
The volume buttons also appear to be different, being slightly more sunken as opposed to sticking out slightly. The mute switch also seems to have disappeared, with just a hole in its place. That doesn’t necessarily mean that the iPad Air 2 won’t have a mute switch, however, as production mockups often have such omissions.
Source: http://www.macrumors.com/2014/06/17/ipad-air-2-touch-id-volume-speaker/
