I think that right now he's probably in the 4-5 range as far as big men in the game today If i had to pick a big to start a team with, KG, Duncan, and Bosh would probably be higher on my list, and maybe Amare or Brand. I would have to decide if I thought it would be easier to teach Amare how to play defense, teach Howard how to play offense, or just be safe with the all-around solid Brand.
My fear for Howard would be that if he can't learn how to play offense effectively, he will be too much of a liability when he loses some of his athleticism in a few years.
I am also remembering Shaq as being quite the nimble big when he first came into the league (or is my memory failing me?), so would it be fair to call him an aerial Shaq, or just the second coming of Shaq?