Apparently, Hecarim is now up on PBE! Get him while he's hot!
I've been trying, but the custom games are currently limited to 2+ real people only, and the bot games are filled with people trying to play Hecarim.
Oh wait I'm in a lobby with him right now... haha, nobody dropped. I'll post my thoughts on him in 20 minutes or so. Behold the light of the Shadow Isles!
edit:
Penguinofhonor's First Hecarim ImpressionsClarifications of his skills:
Passive - The ratio is 10% on the conversion. Early game I was getting +1 AD. Lategame I was getting +20. Lategame during the end of the E charge, I was getting +60.
Q: Rampage actually has an effect. It's AOE physical damage, but if you hit anything with it (the number of targets is irrelevant, it only matters whether you hit anything) you get a rampage stack and the cooldown is reduced by 1 second. You can have up to two rampage stacks. This gives Hecarim a very skarner-esque feel. This ability does half damage to minions.
W: Pretty much works as expected. You heal for 10/15/20/25/30% of
all damage dealt to the targets, and there's a cap on how much you can heal from minions. The minion cap is ridiculously low. Like, 200 HP capped from minions at level 5. They really don't want you to get ridiculous sustain from this.
E: The movement speed boost works like powerball. You'll get up to +400 movespeed, it's pretty ridiculous. And the knockback is actually sizeable - I was thinking it would be like Maokai's, but it's actually like 2/3 of Alistar's in distance. This has a really long cooldown.
R: Hecarim doesn't have to go the full distance of the charge, but the clones he summons always do. So if you charge half the max distance, the clones will charge past you. The enemies run directly away from you - it's not a fear.
Actual review:
So I played him as a jungler. His combination of AOE damage with slight sustain, alongside his movespeed-boosting E, make him feel a lot like Udyr. You have to position yourself better because your CC is a knockback instead of a stun, and that has both its advantages and disadvantages. You can deal a lot of damage if you stick to someone and let your rampage cooldown get really low, but you're probably not going to cast it in a gank more than 2-3 times. It'll still be a good chunk of damage.
His ult is a little hard to aim, but that's probably just with it being a weird dual skillshot thing that I don't really understand fully yet.
I'm pretty much definitely going to buy him. I say he's higher in tanking ability than Cho'gath and Volibear but definitely not up there with the ridiculous CC toolkit tanks. He can initiate and he has one single target CC in addition to his AOE CC, but he also has a lot of damage over time that you'll punish people with if they don't focus you. I think a team could definitely use him as their main tank, but your squishies will have to protect themselves slightly. You're not Leona or Nautilus here.
His kit feels pretty cohesive - you basically charge in and rampage over everyone else's face. There are a lot of opportunities for teamwork with his W and E, but he does have a basic playstyle you can get into without much intimate understanding. I know I did.
Go triforce+tanky (his Q gets down to like 1.5 seconds with two stacks, you can proc it constantly) or straight tanky depending on your role in the team and whether you get fed.