The "Air" will last one product cycle, same was as the Mini. It's a compromise. When people get their hands on it they decide wasn't worth the hit in battery life and features and sales plummet. The battery life always hits these smaller devices hard. Thermal management is an issue as well.
120Hz refresh rate should have been iPhone wide years ago. Apple is behind the competition here.
Material changes? So wait, you run ads with TITANIUM in giant letters above them telling me how great TITANIUM is and go to aluminum frames for all phones including the Pro and you're gonna convince me this isn't cheeping out? The billion dollar company pinching pennies and cutting corners. Sounds like they WANT to push people to Samsung.
New Wi-Fi chip. Well, I suppose. How fast CAN I stream cat videos? Wait, cat videos are kinda awesome.
RAM increases and chip speed increases are pretty standard stuff.
We hear "vapor chamber" heatsink every year. EVERY YEAR. And it never comes. Psst. It's not coming.
25W wireless charging would be a nice upgrade, but no game changer.
I'll pay the extra coin to upgrade early like I do every year. I'm not going to lie and say I'm not. I'm a sucker for the best camera (why? To take cat videos of course!). This is how I "treat" myself every year. I get a new phone a few months before my yearly vacation so I can take nice(er) pictures on my trip. I'm OK with it. It's not a rational decision. I'll probably even order on launch day and wait for the UPS/FedEx driver.
But the thrill is gone. It's about as exciting as buying a new fridge.