Add more sizes (I'm sure they're coming) and I'm sold!
One thing often overlooked in regards to speed on dual cores: it really comes into its own when running MORE than one app. Which many people commonly do. Test just one app and its a question of how well its optimized for multiple CPUs. But test real-world use and you may find even greater benefits.
ALso, yes, the screen is very slightly shorter in inches. AND WIDER. And larger (thus more readable) overall. It's a new wider shape which now matches the 16:10 widescreen shape of most other Apple displays, and is better than ever for movies. Previously, the 15" PowerBook had been a little more "square" than that. In addition, Apple was limited to whatever displays are actually available that are this bright and clear. I don't see why the 60-pixel difference bothers some people so much, especially since it's still higher than PowerBooks had not too many months ago--the same as the 17" used to be.
Specifically, the old PowerBook G4 15.2" has a screen 12.7x8.4".
And the new MacBook Pro 15.4" has a screen 13.1" x 8.2". SLIGHTLY shorter, but wider too. With 94% of the pixel workspace. Nothing to complain about for me.