OS X already supports Nvidia chips, if you're talking about software issues.
AMD and Nvidia use the same type of physical interface, if you're talking about hardware issues.
You're clueless.
As I'm sure you noticed, my post was a reply to the infamous "the customer has the right to choose" quote coming from an apple fanboy.
If the customer has the right to choose, then apple is shit, because they won't let you choose. End of discussion (from that point of view).