Mac OS X is designed and supported to only run on Apple's machines, but a notable percentage of the netbook community has shoehorned the operating system into their modest portables.
Thanks the Apple's use of Intel hardware, certain models of netbooks – such as Dell's Mini 9 and 10v – are fairly comfortable running Mac OS X. But Apple doesn't seem to be impressed, if signs from an early Snow Leopard beta update are to be believed.
According to this post on InsanelyMac forums, a developer build of Snow Leopard 10.6.2 is incompatible with netbooks running the Intel Atom.
Melkort, a programmer known for his works on the Dell Mini netbooks, wrote in the MyDellMini forum, "It does turn out that the 10.6.2 kernel reboots before it's finished loading (before the bsd subsystem is initialized I believe). Might be a chameleon thing, might be an atom thing (as I haven't tested it on any other machines). I'm looking into it, but the 10.6.0 / 10.6.1 kernel works fine with 10.6.2."
Apple has a history of blocking out unauthorized uses of its software (just see what the company has done to lock out Palm Pre and iTunes syncing), so it's not surprising if Hackintosh netbooks were targeted for termination in the upcoming update.
Those running Hackintoshes with Intel Atom CPUs should beware of the 10.6.2 update.