This is serious issue.
My family business in graphic design has relied on Macs since late 80s. Every Mac we've got we've kept it to this day, all 12 of them
Eventually in mid 90s we got our first PCs and just like with our Macs we kept upgrading them every few years (but unlike Macs we never kept the old ones). I was a witness as PCs were closing the gap in graphic design and desktop publishing industry in last 10 years.
My point is that I got my work done no matter if I worked on PC or Mac. I do have opinion on both of them and I have to say that there is always something that one does better than another.
When using Adobe software Macs always had greater performance and somewhat better stability compared to Windows but they suffered from bad interface and some illogical solutions. For example Mac interface required you to maximize your document to avoid clutter on desktop interfering with your work. By doing that you always had pallets kind of getting in a way of your document. Yes it's such a small thing compared to performance issue on PC but it always had me going. They finally fixed it with CS4 (it took them forever but better than never) and now I have to say that its close to a perfect for a Mac user.
Except the fact that Adobe fixed performance issue with Windows and not only did they just fixed it but they surpassed it with Photoshop 64bit implementation. And for some reason I find Illustrator and InDesign running on Windows as smooth as on OS X. So gap between PCs and Macs is now definitely closed when it comes to Rasters, Vectors and Layout.
Now questions are: Is Mac Pro still the standard for graphics and desktop publishing? Yes but so is the PC. Is Mac Pro worth the premium over PC? I am not so sure. For a fact if I was starting the business today and I had limited resources i would go for Windows.
Apple completely dropped the ball with Adobe. Apple does not have their own alternative in graphics or layout to pair Adobe (unlike in video and audio) and they will never have so my greatest fear is that they will just let it die. Kind a like if we can't have it neither will Adobe. I hope I am wrong but CS5 will give Windows even more features and even better performance compared to OS X than what has today.
Apple is definitely shifting the focus to consumers and for their good I hope they don't loose ground in video editing and audio production like they did in graphic design and video compositing.
What might be the solution to this and how can Apple improve the relationship with professionals? I am not sure but if we take a look at the iPod as their most successful product in history and it's business model we can see that is completely opposite of what Mac Pro stands for and what professionals expect form Apple.
Its cheaply made, it has horrible sound reproduction and on top of that it uses compressed audio that sounds bad to begin with and it relies on inhouse solution only (that's iTunes), no third party support is available.
Just like every audiophile stays away from iPod and ridiculous MP3s, most professional 2D digital artists would do the same and stay away from Apple if Apple applies this business model to their future Macs.
Like I said this is serious and we didn't even touch other issues like BD.