The 12" now comes with a 1.5GHz G4, with the 15 and 17" models shipping with a 1.67GHz G4. All the models now comes with 512MB of memory as standard, Bluetooth 2.0, a sudden motion sensor, a scrolling track pad and updated graphics cards.
The updated graphics cards are probably the killer feature as the 15 and 17" PowerBooks now get dual-link DVI with 128MB graphics cards allowing them to plug into the Apple 30" Cinema HD display.
Talk about a desktop replacement system; a 15" PowerBook along with a Bluetooth Keyboard and Mouse and a 30" Cinema Display for the office. Nice...