I think they will be the same as now. In my opinion, the next and last G4 PowerBook update will come soon, with lots of little extras like backlit keyboard and FW 800, a minor speed bump, and some price cuts. Then, when the G5 PowerBook comes out in the 1H 2004, the prices will go back up to the prices as they stand today.
I am basing this on the fact that the last incarnation of the G$ Power Mac did something similar, with the last update in late January with steep price cuts. When the G5 Power mac debuted, prices where higher, but not that expensive when compared to the MDD Power Macs, which where released in August of 2002.