Not Updated For Current Season
I haven't tried this yet. You probably shouldn't. It's just an idea I had for Kennen.
It revolves around using attack speed to get free marks, and then uses synergy with Guinsoo's to do the core of your damage. The damage should be comparable to Yi, Xin, Trynd, or any rageblade champion, but add some range and utility.
The weakness of the build is the same as ADC Kennen; no early Zhonya's. Normally, he needs it to survive team fights. You eventually pick it up for late game team fights and typical Kennen strategy. This build is ideal for someone used to positioning like an ADC. It comes with a lot of escape potential thanks to Kennen's kit and swiftness boots, but you have to be preventative rather than reactionary.
Counters to this are long range ADC's like Caitlyn, and Tristana, and Assassins. 'Don't get Blown Up' is the name of the game.