There doesn't seem to be any iBook issues mentioned so far, so I'll share the two that I know of:
1) There is an issue with the display cable being chafed by the screen on opening/closing, which causes the display to become very temperamental. I was told by a technician that the cables can't be purchased without a whole new LCD! That's rough.
2) There's a logic board problem, that I personally experienced. This problem seemed to affect a bunch of iBooks from 500-900Mhz, almost purely G3's. The G4's are newer so we'll have to wait and see about them. Check out the <a href =http://www.petitiononline.com/ibook123/petition.html>petition</a> I signed at #464, about 2 weeks ago. I sincerely hope Apple does something about this, as it's affecting a growing number of people.
"Blessed is the man, who having nothing to say, abstains from giving wordy evidence of the fact." - George Eliot (1819-1880)
Powerbook G4 / 1.67 Ghz / 15" / 80GB / 1.5GB RAM / Superdrive / new high-resolution display / backlit keyboard (survived car accident!)
iPod photo 30GB (burned in car accident)