3 reasons why this decision by Apple makes sense:
1) Apple is a hardware company -- always has been. If they're going to sell more hardware as a result of this then that is good.
2) People were going to hack their machines to death in order to get XP to boot. So rather than face a customer support nightmare, Apple stepped up to the plate with a safe and easy way to boot windows.
3) When/If Vista is released it will have very few, if any, advantages over OS X. At that time, OS X will be well into it's 5th revision and very near it's 6th. Vista will be brand new, and jast as with XP, there will be a host of issues. Not to mention, it'll take forever for the majority of Windows users to begin adopting Vista over XP. It was enough of an issue to switch to XP in the forst place. Not to mention, M$ doesn't provide the monitary incentive that Apple does to use it's system software.
Boot Camp: Apple's Insanely Bad Idea