[Zammy-Sam]

The Sony VAIO VGN-X505VP is a very slim pc notebook that has a similar order of keyboard and laptop-"body" as you desire the powerbooks to have. I read reports that due opened lid the laptop gets rather unstable. The weight of the screen and the laptop-"body" is almost equal and during typing it happenes that you cause the laptop to shake and fall off your lap. All testers desired the keyboard to be closer to the screen, so they can hold the laptop with their hands while typing.
I can support this. When I am using my tibook on my lap, I tend to press the book against my lap using my hands. They are comfortably sitting on the space next to the track pad and giving me a great balance even in a shaking train.
The thing about an additional mouse is, that I can't deal with it i.e. in the train. A track ball would make much more sense, but I don't see any differences between a track ball and a touch pad. Of course, if your powerbook becomes used_on_tables_only, then there is no need for a touch pad when you have a mouse around. But as the powerbooks are made for highest mobility, the concept of an implemented touch pad that doesn'T waste any space is very good.