ibook ibook ibook!!!!!!!!
IMHO, Apple offers no worse deal right now than the 12" PB, at least as compared to other macs.
The PB has these advantages, so far as I can tell:
bigger HD ($50 upgrade from apple)
BT built in ($50 upgrade from apple)
DVI (but can use spanning hack on ibook)
audio line-in
twice the video memory
130 mhz faster processor
faster bus (133 to 167)
faster RAM (266 to 333, I believe)
Now, that sounds like a lot. But, the price difference is $350, with a combo powerbook, upgraded HD and BT on the ibook, and edu discount on both. You're paying $350 for 130 mhz and 32 video RAM. The overall difference in speed between these two is going to be *negligible* (except in games where the extra VRAM matters). I doubt you'd notice it without doing tests.
No way the powerbook is worth it unless you've got $350 that you don't really need.