Unless we're talking about promo skills only, the answer is never. I'll admit the guy has made improvements but he still sucks in the ring. In order to be one of the all-time greats you need to be great across the board. All that The Miz has going for him is his promo skills and his work ethic. It takes more than that to be bigger than the midcard. He should never have been WWE Champion and I adamantly stand unchanged in that opinion. He's a good Intercontinental Champion (the best recent one as much as I hate to admit it) and a good talker. That's it. He's nowhere near guys like Jericho or Orton, let alone Hogan/Rock/Austin/Cena.