I have mixed feelings about this, but I'll console myself to knowing that Apple doesn't do anything in a vacuum without it fitting into a longer term business strategy.
It doesn't help Apple to create drivers to support all of its unique hardware capabilities on Windows -- Apple's big sales proposition to customers is seamless integration and ease-of-use, so bringing that to the Windows OS platform kills OS X. It also doesn't help Apple to support competing products/technologies in Windows for the same reason stated above -- where, then, is the advantage to having OS X which only runs on Mac hardware?
With Boot Camp, Apple is testing the waters to see how switchers will respond while only providing a half solution to what is a big need among Mac users, which is to run a virtualized Windows OS at full speed within the Mac OS itself to fill in software gaps. If we look at what Apple has done today, its short-term impact will be to make the Mac hardware an attractive purchase option for Windows users who would otherwise be considering a Dell, Toshiba, HP, etc.
However, it is the long-term impacts I'm worrying about. If you can boot into Windows XP or Vista on your Mac in a fast and viable way, why would anyone develop commercial software for Mac OS X? Wouldn't it just be easier, and financially smarter, to develop only on the Windows platform knowing that not only will it run on all Windows-based PCs, but also on the Mac in Windows mode? Where is the incentive to continue developing for Mac OS X when one Windows version will run on everything including Macs?
Apple is rightfully betting that doing this will spur Mac sales, thereby significantly increasing Mac market share. But to those who don't know any better (i.e., the vast majority of consumers), won't they just end up seeing the Mac as another Windows PC? And won't developers do the same in order to maximize development resources and still reach the same audience PLUS Mac users?
Perhaps I'm missing the bigger picture that Apple can see, but this is as much bad news for OS X as it is good news for the Mac's market share. I do see it as a possibility that while the Mac market share may double or triple, some large (and very important) developers may see it as an increase in Windows market share and opt out of OS X development altogether. If a developer such as Adobe were to opt out of OS X development entirely in favor of adding "Mac users: install Windows XP on your Mac to run this software" to the system requirements of every shipping Windows version of its software, there would be no viable OS X software alternative and users would be FORCED to switch to Intel and install Windows in order to run future versions of Adobe software. If Mac users somehow revolt and refuse to upgrade, fine, then Adobe feels the pain of 5% of its user base while to the vast majority of its users it makes no difference. Ultimately, won't Adobe save a lot of money by developing, testing, distributing, and supporting a single platform?
Anyways, just some thoughts and ramblings. I hope Apple has some big surprises in store for Leopard that will blow Vista out of the water to give OS X a real edge -- and I suspect Apple will be doing just that otherwise it wouldn't have made this dual boot option available. I also hope that Boot Camp is a precursor to running a full-speed virtualized version of Windows (with hardware accelerated graphics) within OS X itself. That will give those of us in a production environment a real reason to use it. At the same time, I hope that none of this means less development for Mac OS X.