I think of him in two different ways, the freak that really had turned people away from him, but before that it can not be argued that he was one of the biggest superstars of all times.
He had a huge impact on pop music in general, and had a big effect on many performers. He sold out some of the biggest arenas throughout the world, and for thousnads he was a true icon.
I think also that people in their 30's to 50's are going to be affected and think this is a bigger deal then someone in their twenties or younger. Thriller is the largest selling album of all time, so it can't be denied he had a huge impact at one point. Hell it was big enough that ever since the new broke yesterday mtv has been doing nothing but showing his music videos, so that should tell you something, when was the last time mtv showed a music video :)