Nigel, Yeah, I agree that TyRam can get away without Mewtwo. It's the one deck that can do that. But decks are getting much more aggressive. If you go down two prizes against a Mewtwo deck early, a Mewtwo of your own can be all you need to come back.
I'm predicting Mewtwo to be in every single cutting deck this format. It's simply too good if one player is running it and the other isn't.