The jump in processor speed from 1.5GHz to 1.67GHz also includes faster graphic chips, faster hard drives, and a faster 8X SuperDrive.
12-inch models
1.5GHz PowerPC G4 processor with Velocity Engine, 512K SRAM on-chip L2 cache, 167MHz system bus
512MB of PC2700 (333MHz) DDR SDRAM; support for up to 1.25GB
15-inch models
1.67GHz PowerPC G4 processor with Velocity Engine, 512K SRAM on-chip L2 cache, 167MHz system bus
512MB of PC2700 (333MHz) DDR SDRAM; support up to 2GB
17-inch model
1.67GHz PowerPC G4 processor with Velocity Engine, 512K SRAM on-chip L2 cache, 167MHz system bus
512MB of PC2700 (333MHz) DDR SDRAM; support up to 2GB
The storage is now upto 100GB and all in 5400 rpm.
Superdrive is now 8X and can write DVD+R media as well.
15-inch and 17-inch models have dual-link DVI functionality support for connecting to 30-inch Apple Cinema HD Display.
And they are US$100 cheaper then previous models.
http://www.apple.com/powerbook/
UserAgent: Mozilla/5.0 (Macintosh; U; PPC Mac OS X; en) AppleWebKit/125.5.6 (KHTML, like Gecko) Safari/125.12
3.0 
My Powerbook 17" was ordered before the NEW one came out. But I had still not received it, so they upgraded it to the new one. In fact Apple sent me email saying I might even be able to get some money back! I suppose it was ordered at a very good time! 
