So far, each new version of OS X has had the name of a cat. Cheetah, Puma, Jaguar, Panther, Tiger... All two syllables, which makes me think the next release will follow the same pattern. This rules out Ocelot and Lynx. A potential candidate is Lion, but this name seems too... common, especially when preceded by Tiger, which is why I believe the next release will be called... *drumroll* Leopard edit: No wait. Cougar! Much better.