Erm... excuse me if I'm wrong, but didn't Reggie say before the end of September, and that it would appeal to hardcore players?
I'm sorry to disappoint, but I think he may have been referring to the Metroid Prime 3 Preview Channel.
And before anyone says the game is already out (ie before September), a late demo channel would still assist those who didn't buy the game at launch.
But I'm probably wrong. Someone correct me.