Well lookieeeee here. It seems there's been an over-eager Apple employee manning the iTunes store today, hitting the big red button marked "PUBLISH iPAD AIR 2 MANUAL". Tim Cook's crew may have just indadvertedly outed its own refreshed tablet line.
Head over to the iTunes store and you can download an updated version of the "iPad User Guide for iOS 8". In it, explicit reference is made to an "iPad Air 2" and an "iPad mini 3", each shown in a diagram to have a TouchID sensor. There's a later reference made to both having cameras capable of shooting burst-mode photo batches, too.
While the manual doesn't give much more away on the two tablets, just take a look at the iPad Air 2 in that screengrab above -- it's looking very squat, no? Is Apple about to change the screen ratio of its tablets? Or is this "leak" a red herring, designed to throw us off the scent of what Apple's truly planning to launch tomorrow?