The Register outlines an imaginary future for Apple, now that Apple is providing the Boot Camp utility to support dual booting Apple hardware to XP or OS X. The real risk comes if Leopard really does run using virtualization technology, allowing Vista software to run seamlessly alongside OS X. At that point it's all too easy for Adobe or Microsoft to write XP software that fits that virtualization layer, rather than write OS X software.
It's a genuine risk, the counterbalancing force being that Apple is increasingly writing its own software for OS X. Aperture is a mean competitor to Photoshop for many users.
I hope it goes well. From my perspective it means if my old XP desktop ever chokes, it will be replaced by a MacBook. Similarly if I ever decide I need a Vista machine, it will be made by Apple.