Ah, ok. So it looks like my information is out of date, and Apple isn't shipping a TPM anymore. But they did, at some point, use a combination of hardware and software to try to prevent users from running OS X on non-Apple hardware (or a VM)?

Even if they didn't, the EULA still forbids it. And I'll take "Please don't use this software on this platform (but we won't stop you)" over "Don't use this software on this platform (or we can sue you)" any day...