<more geek speak>
I've got a rerun of the ScreenSavers on in the background and they just pointed out that the iBooks now also have 512K of level 2 cache. That probably accounts for the snappiness that I've been experiencing.

So, an Apples to Apples comparison of the 12" iBook and 12" PowerBook:
iBookPowerBookProcessor Speed
(which diehard Mac users
will say doesn't matter)1 GHz1.33 GhzLevel 2 Cache512K512KShipped RAM256MB256MBSystem Bus100 MHz133 MHzHard Drive30GB60GBOptical DriveDVD/CD-RWDVD/CD-RW
(DVD-R option)WirelessAirport Extreme ReadyAirport Extreme and Bluetooth includedPortsEthernet, 56K Modem, two USB 2.0 ports, one FireWire 400 portEthernet, 56K Modem, two USB 2.0 ports, one FireWire 400 port, one FireWire 800 portDisplay1024x7681024x768GraphicsATI Mobility Radeon 9200NVidia GeForce FX Go5200Dual Displaywith hackyesAudioheadphone out, built in microphoneline in, headphone out, built in microphoneWeight4.9 lbs4.6 lbsList Price$1099$1599
Really?? $500 for a line in jack, 33% more speed, 30 more GB and .3 lbs less? Is it worth it?? If you factor in $99 for the Airport Extreme card and $50 for a Bluetooth module, I guess it narrows the gap a bit.
<geek speak ends>