I think people tend to get a little 'performance happy' when it comes to doing things with technology. Professionals have been using Photoshop to run businesses and interface with whatever camera/video/editing software for quite awhile on PPC macs for many years now. An Intel Mac will do pretty much the same thing on the newer hardware with Rosetta even without the 'nativeness' in pretty much the same way, even on the consumer grade Macbooks. It will only get better when Adobe and other software producers produce the Universal binary versions. Once that happens you will be ready to go with it for your business without the virus/spyware/malware issues that plague the windows world.
So really, you can invest in your photo platform in the windows world, where it certainly works well enough but you have to contend with the issues that are involved in the windows OS, or you can invest in the Mac world, which is geared specifically to the creative arts. The Mac as it is works wondefully with Photoshop, video editing, and other graphical endeavours as it stands today. It will only get better in the very near future, and with the same hardware that you can buy now. With a Windows PC/laptop you will only get empty promises that are generated by a marketing juggernaut leveraging its monopoly over the masses.
Apple doesn't really seem to market as much as it just makes good hardware with which its software works as flawlessly as any software can. It is also much more enjoyable to use and look at for hours on end. Of course with certain caveats, as always, but in my own experience over only two years of using a Mac I don't see them doing anything that would prevent professionals in the graphical arts from effortlessly creating whatever the hardware is capable of doing. And this includes professional TV and movie producers.
I used to think that Apple hardware was always overpriced for what it did, but now that I have used one for an extended period I am convinced that it is worth every penny. I'm not a fanboy either. I still use (professionally) Windows and Linux computers but for my own needs (and if I were to start an independent business) I will always use a Mac from now on.