512Mb RAM is now standard across the board (which means 1.5Gb max for iBook), which I think is probably the bare minimum to have Mac OS X running smoothly. Not much has changed for the mini, but iBook revision has again put it into the value bin. There is a speed upgrade (to 1.33Ghz and 1.42Ghz G4), memory upgrade (to 512Mb) and video upgrade (to Radeon 9550). It also gains the new trackpad and motion sensor from PowerBook. Still costs AUD$1,599 for 12" and AUD$2,049 for 14". Expect to pay less from other resellers.
My 900Mhz G3 iBook still runs Panther alright so there is no urge for me to upgrade. Well, after some struggle trying to distinguish between "need" and "want" anyway. Notebooks are really getting cheaper now. If there is no need for raw processing power (which I'll say 80% of users who don't play latest 3D intensive games), it is actually more practical buying a notebook than a desktop, if word processing, Internet surfing, email sending and instant messaging are the most common operations. Cheap Celeron M (i.e. Pentium M w/ half the L2 cache) lappies with desktop parts and shared video are now just above AUD$1,000 range. $1,500+ iBook, though maybe more refined, might still be considered expensive by some. Then again, it is already much much cheaper than 2-3 years ago.
Another benefit for dropping Mac prices might be the second hand market. Mac used to retain its value well, but with newer and faster Mac coming out at much reduced price, you'll expect to pick up some pre-loved Mac for even lower price as well. Needless to say about the up-coming Mactel.