some good posts on this thread, and a huge amount of bullshit as well. Anyone who says that a certain type of training will definitely work for everyone, has no idea what they are talking about(madcow, not directed at you as you know your stuff).
Some people cannot train each bodypart 2x weekly, and make any kind of gains. I happen to be one of them, in all the years I've spent in the gym(around 15), I've tried every approach to lifting that I could find. And training everything 2x weekly....all that did was lead to overtraining in a big way! I can specialize on certain parts, hitting them more than once a week to bring up weak areas, but sure as hell not everything.
To those preaching about their 2x weekly training, I would love to see some pics of your physique, as well as see your routine and what kind of weights you are moving.....when you are not all that advanced, you can get away with almost anything