Dan Turner has written a very informative article about Apple Computer's design process in Technology Review.
He couldn't get access to anyone now at Apple, so he interviewed a number of former Apple people. Yes, I'm in there as well.
The article does an excellent job of showing that good process is useful, but a strong leader, with good taste , an excellent eye for detail, and the strength to lead a team to focused, cohesive design makes all the difference between good design and great design.