Of course Apple does usability testing and has since the beginning. Here's a full guide on how they do it:
http://developer.apple.com/mac/library/documentation/UserExp...
Obviously they use their own judgment and market feedback as well, but the notion that they launch products without testing them first is crazy.
No one is saying they aren't testing them. Of course they are.
They are just not testing them in any normal sense.
I.e. they don't invite users to test it in usability labs or any other typical test environments.
http://www.businessweek.com/magazine/content/05_12/b3925608....
Apple don't do any kind of usability testing in any normal sense.
They build products they want themselves and then they see what happens. The feedback they get back from that is the feedback they use.