Apple appears to be removing support for Intel Atom processors in the forthcoming 10.6.2 patch for Snow Leopard. OS X Daily is reporting that the update kills support for the processor, which is primarily found in netbook and nettop computers.
Apple doesn't sell any machines that have Atom-based processors, and the licensing agreement explicitly says that OS X is not permitted on hardware that's not sold by Apple. Despite that, there's a large and growing community of modders that build "hackintoshes" that run the OS.
The tech company has a reputation for heavy-handed comedowns on these groups, including a whole pile of legal threats to Psystar - a company that sells custom-made Apple machines. This move is regarded by many to be an attempt to shut down the hackintosh community in the same way.
However, groups of modders invariably move faster than big tech companies, so it's unlikely that it'll be long before a version of the 10.6.2 patch that works absolutely fine on Atom processors is found in the wild.