I completely understand that getting the G5 chip to fit in a 2" enclosure is a big step forward, but it seems that people think that the iMac G5 was designed last week and built yesterday. The iMac G5, I can assure you, has been in the works for quite some time now, possibly more than a year or more. G5 PowerBook production isn't waiting to start until the iMac was released -- I'm sure they were/are designing both concurrently.
The enclosure of the iMac has nothing to do with the PowerBook, though. You can fit a G5 chip inside a matchbox and it'll run, as long as it's cooled sufficiently, and the iMac's design, while rectangular and thin, stops there when it comes to similarities with the PowerBook.
I guess I'm just trying to get at the fact that getting the G5 chip to fit in a 2" vertical enclosure does not further the production nor hinder the production of the PowerBook. It does nothing to the advancement of the PowerBook, since the designs are very different, and both use very different cooling systems.
The iMac is used in a "vertical" position, and hot air has a tendency to rise. The addition of small, low-rotational speed fans helps this process along, cooling the G5 enough for normal operation. We all know that the PowerBook isn't designed like this at all. You need a stronger fan, since you gotta take air in from the sides and expel it from the sides. Plus a whole lot more scientific stuff that I can't think of right now...
At any rate, they look the same, but are radically different, and borrow very little from each other in terms of design.
Speaking of which, I'd like to ask a question now instead of being a pompous ass for once... hehe... since the G5 is different from the G4 (hell,
none of the G4 chips required cooling like this bad boy does), do you think we'll see a
redesigned PowerBook, or do you think Apple will try and keep the form similar to the PowerBook G4?