Well, to be fair to Apple, the new Retina MBP’s do support a ton of shit that the old OS wont be able to use, stuff they dont advertise that well, like hardware accelerated AES instruction sets, which FileVault can use so that encryption works super fast, and almost 0 cost to the CPU.
Same for the new Airplay Mirroring APIs. 10.8 does leverage hardware in ways 10.7 can’t. *shrug*