I had a chance to play with the 12'' PowerBooks yesterday (they didn't have 17's on display yet...) Here are a bunch of my observations, if you were thinking of buying one:
1) It's a miniture iBook with a G4, in case you didn't already know. It's so close, that I mistook it for an iBook with the lighting in the room! It is a good bit smaller than the iBook, and it feels a lot more solid though.
2) It gets pretty hot while it's running, but this thing could fry eggs if you leave it on while you are charging the battery. I couldn't keep my hand on it for more than 5 seconds without some pain.
3) It's speedy. I ran a few photoshop tests, and it seems to be nice and fast. Too bad none of them had Quake 3
4) Battery life is excellent, better than that of the iBooks. You could actually get 4-5 hours
with Airport wireless on. I only played with it for 3 hours, and it said it had about 40-45 minutes left when I was done.
5) The keyboard didn't feel that cramped while I was typing, but the function keys were small enough to bother me.
6) It has the same great external monitor support as the 15'' PowerBook.
7) Airport extreme rocks. As usual, the Apple store and Tekserve had their own wireless networks for me to play with. Transferring files was nice and fast (I got a full signal, BTW) probably a little under half of what my 100 MBps wired network at home does, which is right on par with Apple's claims.
OK, that's it for my input. In case you were wondering what I was doing in Tekserve for 3 hours, and in the Apple Store for 1.5 hours, I was having my PBG3 checked out...