While it’s already been revealed that there are certain spec requirements for installing Apple’s upcoming OS X Mountain Lion, certain 64-bit Macs will also be unable to run the new operating system when it ships this month. Following the release of the Mountain Lion GM to developers, Apple has an official list of current Mac models that are compatible with Mountain Lion.
If your Mac doesn’t support the current OS X Lion already, don’t expect to hop on the Mountain Lion bandwagon later this month.