I was really hoping it would be a new unique Endless Spell that everyone could use. Instead, it's a 400 point beast that can crush pretty much anything. Sniping the hero is definitely a weakness, but I think people will still be able to throw it at your army before it hits their own even if you do kill the hero early.
The rules in it's wild state say that it can run and charge, it has as 12in movement, and the player who brought still gets to control it's movement. So if you snipe the hero turn 1, they'll still run the Incarnate towards you and most likely either get it farther than 12" away from their own units, or within range of your units. It also get's more powerful in wild mode, so unless your opponent bound it to a really important hero they'll probably just laugh and watch this thing tear your army apart while they just go for objectives. Most units will get no save against this thing's attacks, so you're just praying it rolls a lot of 1s or say goodbye to whatever target it attacks.
It also has a "can't be killed" rule that makes it very hard, but not impossible, to take out turn 1. The rule says the roll takes place in the battleshock phase, so I assume that if you somehow manage to damage it in your opponent's turn through overwatch or some other way, you can possibly bring it down. Still, it has another random death mechanic that works like Kroak's, which I already dislike. Sometimes you'll bring it down by dealing a few damage points per turn, but it looks like you have to deal at least 10 damage to it to make it likely to go down a state.
I guess the positive is that armies that are lacking in big beatsticks will love it, and armies that already have plenty of damage output will avoid it. Still, I can see some crazy combos like taking Morathi and this thing, ensuring that you just simply can't snipe the controlling hero for a long time, giving the Incarnate free reign to rampage through the opponent's army. Or just binding it to a Maw-Krusha or some other really big, tough hero and just laughing as you get ripped apart by two massive monster. I don't like the anti-Endless spell mechanics. You can already dispel them pretty easily, so having this thing literally get more powerful by feeding on them just seems like GW is telling you not to take Endless Spells.
All in all, this thing seems like a melee army's dream. I buffs your casters while debuffing others, lets your friendly units get all-out-attack in an AoE, lets you re-roll run and charge rolls, prevents units from retreating and is a melee blender on top of that. Is it worth 400 points? I'm honestly not good enough at AoS math to say. But I personally do not think this thing is going to be fun to play against or with. Which is a shame, since I thought the terrain set looked cool and assumed that we were getting a new universal Endless Spell.
