The recent BootCamp announcement is an interesting shift in strategy for Apple, and I think there are two ways to look at this move.
On one hand, they have removed a barrier for people buying Apple hardware. People who like the new MacBook Pro but are either afraid or unwilling to give up Windows. If this was the case, they're basically betting that people will be more willing to try the hardware and then decide to stick around. It's similar to the move they made a few years back by making the iPod work on Windows, and we all know how that worked out.
On the other, this could signal a decoupling between Apple software and Apple hardware. This would be a major shift - until now, they have sold the entire experience from end to end. The iPod was successful because it combined good industrial design with a simple user interface.
I'm sure Apple would love to sell OS X for use on your Dell, but then they realized that it's far easier to get XP working on their limited set of hardware. Microsoft spends a lot of time on backward compatibility and making sure (nearly) all hardware configurations work. This is something Apple hasn't had to really worry about yet. The underlying *nix base might help somewhat here, but anyone who has had trouble getting Linux running on a laptop knows that they can't compete with Windows here yet. (And you know that if someone's camera or printer doesn't work, it's going to leave a serious negative impression of Apple's software). It's just easier to maintain a stable platform and spend time innovating when you can concentrate on a limited set of hardware.
This would be very similar to the direction Palm went a few years back, separating their software and hardware divisions into independent entities. I think it's reasonable to say this hurt Palm in the long run especially on the software side. Palm OS is all but dead, while the hardware continues to thrive. In the process, I would say they really cemented Microsoft as the leader in the mobile OS space.
Apple really needs to ask themselves whether they are a hardware or software company. There will always be a place for well-designed hardware, but the margins are lower. More importantly, they would lose the control they once had. Do you really think Windows Mobile has any plans to support iTunes? With the recent stake taken in Disney and the amazing success of iTunes, I can't seem them giving up the software side of things. And, as discussed, the software side is not without its challenges either.
Personally, I don't think decoupling is the best move, so I would like to think this was a move to spur adoption. That said, Wall St. can put enormous pressure on companies to show growth and expand marketshare, and selling hardware that runs Windows would help, as would selling just the OS- but at what cost? It's almost as if Apple can't win... maybe I should sell my shares.
Where do you see Apple headed? Are they better as a hardware or software company?