He was op because of his E, R, E burst. Since they toned that down and nerfed his base stats and over all tankiness he is certainly not op. His kit doesn't have anything borderline unbalance-able in it at any rate like darius and Lee Sin.
EDIT: Actually I think the whole E R E combo is warping his balance and I am not incredibly attached to it. I think it should be removed, the stun should go up to 1.25 seconds (still reducing the cool down by 1.25) and the cool down nerf should be reverted, plus the slight increase on his Q damage. This way he will have a bit less burst, and a bit more sustained damage, plus a bit more utility outside of ult. Just my 2 cents as a skarner main.