So much weirdness going on in this here thread.
My take on the matter:
The NBA is a business that takes care of it's players and owners. Sure, Donald Sterling has every single constitutional right and privilege to say whatever the hell he wants. But free speech has never in the history of free speech, been without consequence. A policeman, or judge or civil official would not have been able to fine Sterling for what he said (although they did fine him for what he did in SoCal with his discriminatory rental policies, settled out of court) but the NBA has a different set of rules altogether, and absolutely must protect it's bottom line.
If you were a young black kid with tons of talent, would you want to play for any owner that acted like that? What if the league just said, "well, that is Mr. Sterling's private opinion, so free speech bitches!"? That completely undermines the business and the character of the NBA. Sure it is private, but Donald Sterling became a public figure in the eyes of the NBA and the world 31 years ago when he purchased the Clippers, and his actions are subject to punishment by the NBA and what it sees fit.
Personally, I think it is awesome that the old douche bag is going to be forced out of the NBA. It's not like he is going to lose money on the Clippers sale. They are probably one of the most valuable franchises in the NBA, given their market share in LA.