kennen is a strong early game champion in summoner's rift due to the high power and low cost of his thundering shuriken, and his ability to pick up kills with stuns and ignite. he bullies people with thundering shurikens and last hits the entire time, then uses the gold advantage (and xp advantage if he forced a recall which he usually does) to continue bullying throughout the game.

in crystal scar, the early game phase doesn't last nearly long enough for kennen to really gain an advantage and you have to seriously bust your ass to gain any sort of noticeable advantage over the opposing bot lane.

best case scenario he's an off-tank or off-dps. he can't hang with the likes of ryze and yorick.

Quite simply kennen has not had a free week since Dom came out. Whenever a champ has a free week you start to see them in dom a lot more. People want to try him out in this new setting before committing. I have seen one or two kennens but they are really rare.

I played Kennen early dominion as hybrid, before the gunblade nerf & before the new masteries.

Typically any of: Rageblade, Gunblade, Rylais, Mercs, Sheen

Reasonable at windmill, teamfight & team push off tower.

Piss for creepwave clear/bottom laning, against more aggressive pushers. High risk to do a bigger creep wave clear - not so great for defending that sort of assault on a point.

At this point, with the popularity of quickdash champs such as riven, ahri, ezreal, etc. Lightning Rush doesn't work out so well to actually nail them with it in a chase.

Ultimately, I found Ezreal brought more to the table, if I was in the mood to play such a skillshot champ. Kennen just shines better in SR laning and teamfights.

He's not as good a Ryze.

He would make a better top than a bottom. Aoe CC is more valuable when fighting more than 1 person.

He suffers from needing people to understand how to fight with him.

Disgusting comps with Kennen / Riven / Kayle / Yorrick... I've seen them completely wreck people.

as builds on kennen are pretty **** good. alternate lvling Q and W.
Core build: pros blade, zerkers, malady, rageblade, ionic spark, kitaes razer.

Ionic spark complements his aoe stuns, its like having another W..for FREE

look at kennen's leveling stats for ATK and AS, they are amazing perhaps the best in the game. beats out any AD Carry. Looks like teemo's but slightly better

Kennen was picked VERY often in Dominion beta. He carries pretty hard and has high mobility.