A7X and IGZO clearly weren't required to deliver the Air. Think people are forgetting the A5X and A6X were products of necessity as there was simply no way with that generation of GPU to deliver a retina display at anything approaching acceptable performance levels and battery life. IGZO (somehow) wasn't needed to delivery battery life and size so why move from what already works?
Fingerprint sensor would have been nice but it's easy to see why they didn't do it if there are indeed supply problems. Plus it's not as essential on an iPad as it tends to be on the iPhone, different typical user profile after all.
How on earth is the only thing between the Mini and the Air being the screen a *BAD* thing? Good god some people are never satisfied. Now it doesn't matter what you buy, you get the same fantastic hardware (and let's not forget that A7 is a monster and I suspect it may be clocked a bit faster in the iPad's) and can just focus on the form factor that's right for you.
Frankly Apple have delivered a really nice set of products that have very few obvious compromises. Was it predictable? Yeah, of course it is, you're on a rumour site and the tech itself was well known in advance. However go back about a month to before the iPhone launch for a moment. Okay, the next iPad will be almost as thin as a mini, knock almost a third off the weight and have a 64 bit processor with double the CPU and GPU performance from the iPad 4. Doesn't sound quite so bad does it?