Beyond the landscape of Macs (though, those MacBooks are pretty sweet
), I suggest holding off for the next round of product releases. Intel's CoreDuo is the name of the game right now in high-end laptops, but Apple is the only company with a product available based on this new technology.
Technological updates aside, believe it or not, I would suggest IBM/Lenovo laptops. There are two reasons for this: 1.) Their support, warranty service, and built-in recovery features are unmatched, and 2.) The overall engineering of their products is quite good (they are one of the few laptop manufacturers that I am aware of who make a 15" laptop that weighs under 7 lbs.).
If you need more info, let me know.