Actually, running any Mac OS on other than a genuine Macintosh computer is against the EULA.Actually its not illegal, if you purchase it. Steve wont give a damn what you run it on, as long as you buy it. As is the case with Gates im sure -- otherwise there would be no such thing as bootcamp or parallels. Or at least they wouldn't be products that are advertised on the Apple website.
And I would imagine that SJ would prefer that you purchased a Mac and not just the OS since Apple makes most of their money through hardware sales.