Yesterday I got a new MacBook with the matching 24" Cinema Display adding to my collection of macs. [from left to right] 12" Powerbook, Dual 1.8 G5 PowerPC with 24" Cinema Display, the new 24" Cinema Display attached to the 13" 2.4GHz MacBook.
I tested out the speed last night by converting a flash video to a quick time movie file using iSquint on each of the machines, here's how they stacked up.
MacBook w/4GB Ram = 9min
G5 w/1.5Ram = 23min
Powerbook w/768Ram =1hr
I was very impressed. The MacBook runs CS3 and Aperture flawless. Check out the custom wallpapers I made for each.