I don't see why not
I don't see why Apple wouldn't do a powerbook update after March 30. That update is for everyone who bought a PB after the second revision without a combo drive. What's to stop them? A G5 you're not going to see, guaranteed. Those probably won't be out for the towers by then. But a revision? I think it's likely. Maybe we'll see an apollo PB running at 600 and 700 mhz.