So we have more tactics then just sending a mass of troops into the fray? That's a problem? Seems like this might make multiple plays fun when you start using different abilities.
Inventory management was NEVER fun in any game EVER (for me). From the looks of things, you equip the troops outside of combat and their inventory is locked once you enter the battlefield. (speculation)
unlimited ammo except for the rocket launcher
I never ran out of ammo in XCOM, and only had a problem in TftD in the multi-part missions. I think the only reason they singled the rocket launcher out is because it would be incredibly imbalanced if you had unlimited explosives.
armor and items giving special abilities
No different than any upgrade system in other games. It could just be similar to the flying suits giving you the ability to fly, or certain weapons having better accuracy.
New system for movement and attacking. Looks like it could be just as interesting. Plus it's easier to figure out "I have 6 moves, I can do..." than it is to figure out "Okay I have 60 TUs, and I need 35% to fire once, so i can..."
scripted plot-critical missions
Randomized missions are fun, but sometimes a well made level can be even better. Sure it can kill the tactical approach when you find out how to outsmart the AI, but this isn't always a bad thing.
It can be turned off, and it can show you some interesting kills up close.
Yeah, this one I wish they didn't change. But I usually don't build a second base until I research the Hyper-wave Decoder(Best radar in-game) anyways.
Depends how reimagined they are. The sectoids in all honesty were pretty bland, as were the mutons and ethereals. Hopefully they keep the Chrysalids. Those were a proper "Terror unit"
I can't be the only person who preferred to use multiple small squads instead of one huge one. I remember I only trained enough soldiers for the trip to Cydonia, and sacked (or sacrificed) the ones with less than amazing stats. And most missions I left half the squad in the ship. And even than I usually had 1-4 MC troops and the rest where on scout/cleanup duty.
Change isn't always a bad thing, and it looks like Firaxis knows what it's doing, for now.