I have to disagree with the autotune mumbling opinion. Off the top of my head I can't think of any songs where he uses autotune. Not saying he hasn't but it's certainly not the first thing that comes to mind when I think about his songs. And as far as his flow, he is definitely not part of the mumble-rap trend the kids seem to like these days. Remember, he was classically trained on DeGrassi High. :p
Nonetheless, I have not seen the new Rolling Stone list but I cannot think of one Drake song that belongs on it.