Accelerate Your Mac has some benchmarks (run by Other World Computing, link to weird URL here) posted comparing a couple of different machines and some interesting user comments about how to install various versions of Windows XP.
The interesting thing is that it seems the Mac needs to do some Open GL work. The Mac OS is still behind by around 19% on some Open GL tests.
Regardless of the test scores, it’s only making it more attractive to buy a MacBook Pro, even with the higher price tag with all the options I’d want. Even if Dell or Lenovo made a laptop for a lesser cost, I believe the difference would only amount to a few hundred dollars and it’s not going to have some of the nicer design features that the Apple machine has.