Yes, I noticed that too. I got a chance to play with the new laptops at the San Francisco Apple Store (I'm here for a business meeting, and snuck away to play).
The About this Mac... shows 1.07GHz. I can only assume its from a 8x multiplier on a 133MHz bus (1066MHz).
Given Apple's previous branding of the 1.42GHz Dual G4 machine as "1.42GHz" and not just "1.4GHz", and the new 12" PB as "1.33GHz" and not simply "1.3GHz", I'm a little (ok,
very little, but still) surprised Apple didn't market these new iBooks as "1.1GHz", or "1.07GHz" or something.
Either way, the new 12" iBook did a pretty good job at keeping up with a 1.33GHz 12" PB that was right next to it on the display floor. The PB had faster HD access, it appeared, but otherwise it was a very close race.
I think its time to replace my aging 600MHz 8MB VRAM Rage128M iBook
