I don't know about the 12" models as I can't use a screen that small for work, but on the 15" and 17" Powerbooks Apple just added an hour of battery life on the models released this week, in addition to much higher resolution screens. It was disappointing not to see a CPU speed increase, but between adding faster memory, more battery life, better screens, better graphics cards and significantly cutting the price, it was a pretty good piece of news! Time to upgrade.