Your post reminded me about the evolution of mobile phones... Everybody remembers that the mobile phones were like a brick in the 90's. Every manufacturer was racing to make the phones smaller and smaller. They even made a few ridiculously tiny models that weren't successful so that is when they stopped reducing the size. And started adding more features (color displays, cameras etc...).
So when will Apple stop reducing the thickness of the MB(P)s? Until every MB is 1nm thick? Why didn't Apple stick with having as thick as the Powerbooks, but having way bigger battery (15 or even 20 hours of battery) or any of the lacking features other brands have?