You are forgetting about dual-wield DK's.Get rid of weapons with tanking stats.
I know this sounds extreme, but there's not really a hugely compelling reason to have tanking weapons. This is going to be even more true with the removal of defense rating. Just replace that avoidance with agility and turn some of the stam into a socket and you can turn weapons that used to be just for tanks into more broadly applicable pieces of gear (and at the same time, turn fast one-handed dps weapons into more broadly applicable pieces of gear).
While I agree with some of what you said, I don't believe removing tanking weapons from the game is viable without having to rework either A) Raid encounters or B) Tanking armor to compensate for the stats lost on the weapons. Granted, it is really tough to speculate at this point with Cataclysm coming out and imminent changes.