The latest pre-release builds of Mac OS X 10.6.2 apparently break support for Intel's Atom processor, essentially killing the ability to run Snow Leopard on "hackintosh" PC netbook computers.
Apple doesn't make a netbook computer, and doesn't officially support the Atom processor that's used in many netbook models.
Breaking the ability to run Snow Leopard on non-Mac Atom-based hardware could be an intentional move on Apple's part to keep the operating system tightly bound to the Mac. Since Apple doesn't support the Atom processor, however, the change could simply be an unexpected side effect of other code changes.
For those that are already running Snow Leopard on netbook computers, the hackintosh community is recommending users skip the update when it comes out and stay at 10.6.1 instead.
The current version of Snow Leopard is Mac OS X 10.6.1, but the Mac OS X 10.6.2 is expected to arrive soon.
[Thanks to OS X Daily for the heads up.]