Yeah, I was also full of awe when I first saw those fine buttons, I like em better, But maybe Apple will give a choice in a future update for which set, I guess you will see these only on Cocoa apps. They're also in the Calculator.
Hmm -- it sort of makes sense to have sunken in buttons on the metal apps, but how come the rest of the buttons are still sitting on top of the windows, with drop shadows and all? (e.g., the number buttons in the calculator).
This is changed in Address Book also. It seems Apple is making the change to compliment some new hardware that will have a similar look to it. Might be a phone, might be some sort of digital video device, might be a firewire toilet plunger... I guess we will find out in the next couple of weeks.
The brother of a friend, whose friend works for Apple, told me about a new iBook. I can't remember how he went about describing it to me, but I pictured something like a Powebook... its color.