Dave Caolo of TUAW nails it with a piece comparing Psystar to a noisy dog.
To the extent that they have one, Psystar's one point, on which everything about the company turns like an elephant balancing on a pivot platform, is that Mac OS X constitutes the centerpiece of a separate market, one distinguished from the mainstream PC market not only by the incompatibility of software written for one with the other but by a difference in quality that allows Apple to ask (and get) a premium for their computers, and (here's the clincher) that Apple has a monopoly on that market.
Let that sink in for a moment. What they're saying is that Mac OS X is so much better than Windows that you can't really even compare the two, that Windows is like a child's toy in comparison to the craftsman's tool of Mac OS X.
As much as indulging that thought is very gratifying to a Mac-head like myself, the reality is that Windows isn't that bad. Aside from efficiency issues and interface refinements, the biggest difference between Mac OS X and Windows is their differing approaches to application support. Windows basically gets out of the way, leaving the developer with both a lack of constraints and the responsibility for supplying their own plumbing. By contrast, Mac OS X features a carefully constructed framework that developers can tie into in various ways, both imposing some limits and vastly reducing the amount of code they need to write. Some Windows software is quite good, in a very few cases better than anything available for Macs, although the list of examples is dwindling as nearly every major application now has a Mac version. In the long run, Apple's approach is certain to prove the better of the two, but for right now you can still make a case that Windows is ahead. Apple basically admitted this to be the case when they chose to include Boot Camp with Leopard, and now with Snow Leopard, allowing you to run Windows on a Mac, and that point is driven home by the number of copies of both Parallels Desktop and VMWare Fusion in circulation, as well as the interest in developing a cross-platform environment alloying software written for Windows to run on other operating systems without a copy of Windows being installed.
Moreover, for better or worse, Microsoft has managed to establish certain standards that Apple must conform to if they hope to compete in certain markets, Microsoft Exchange for example.
So, yes, Mac OS X is better, in most respects, but the idea that this is enough to so distinguish it from Windows as to constitute a separate market over which Apple enjoys a monopoly, such that laws prohibiting monopolies should be invoked, is pure fantasy. Maybe in five or ten years that argument will begin to hold water, but for now it leaks like a sieve, and Psystar deserves to be slapped down hard.