two comments: 

1. I think someone already said this right, but to be more specific, supervenience physicalism is what the zombie argument turns on. Other versions of physicalism e.g., token physicalism, could be compatible with the mere possibility of a zombie. 

2. The section on inverted qualia and the "neurosurgical prank" is wrong. See in Dennett's online Quining Qualia, "In this version, intuition pump #5: the neurosurgical prank, the experiences to be compared are all in one mind. You wake up one morning to find that the grass has turned red, the sky yellow, and so forth. No one else notices any color anomalies in the world, so the problem must be in you. You are entitled, it seems, to conclude that you have undergone visual color qualia inversion (and we later discover, if you like, just how the evil neurophysiologists tampered with your neurons to accomplish this)." How could a neurophysiologist tamper with neurons and we say there is no physical basis for the inversion? Why call it it the "neurosurgical prank" if there is no physical basis? From SEP: Inverted Qualia, it appears (though they don't reference the "prank" specifically) that the prank was probably designed (by Block and Fodor?) to refute functionalism, not physicalism. Note that SEP and Dennett both quote Block and Fodor but Dennett leaves out the next sentence, "..against Functionalist accounts.."