It's also true that the 'amazing hardware' in the Mac's is basically the exact same hardware in Dell's, though there's a bit of customization in them obviously. So yeah, there's no difference besides the case and the ability to run OS X without hacks.
Uh, EFI doesn't have anything to do with the processor, considering the fact that EFI was created and developed by Intel anyway. 😛
Conroe, Intel's next chip, is amazing. It's not even clocked up high yet (but apparently scales well) and it beats today's fastest chips, which are also overclocked, by a large margin. That's awesome. 🙂