Well, IMO this will end the Tablet game for Apple, because I strongly believe that not every Carrier will accpet this, at least for the Cellular Models.
Below is a Statement of the German Telecom
In englsih "We will not Offer this Device with the Apple-SIM"
As one of the Top Providers in Germany this is huge hit in the face for Apple, because everyone I know buys a iPad with contract and cellular data.
Source:
http://www.stern.de/digital/telefon/apple-sim-im-ipad-air-2-laesst-mobilfunkanbieter-zittern-2146071.html