What do you want to see in LoL?

Another thing i'd like to see: High risk, high skill, high reward champion.
Something like a shadow fiend, for anybody that has played DotA.

Katarina? She's basically exactly how you describe. For the rest basically every glass cannon champ. I think LoL has enough of these incentives. A small example is lux' passive. She's incredibly safe if you just cast spells but popping her passive has some risk with a reward attached to it.