I was always under the impression there were no more than 5 to 8 superstars at once in the league. But when I see names like Aldridge, Randolph and Gasol mentioned in the posts above I can't help but think the word "superstar" has devalued quite a bit. Most of those guys are fringe all-stars at best. Is an all-star a superstar these days?
In the early 2000's it used to be pretty simple to me what a superstar was: a worthy successor to MJ. Hall of Fame type stuff. Prime Kobe/Tmac/Vince/Garnett/Iverson, those were superstars.
Granger? Bosh? Not so much.