I hear more tanks that like active mitigation than not. If they have to completely rely on healers for survival they will find it boring and may just stop tanking. They aren't going to take away a mechanic that has been received so positively.
And you are absolutely clueless if you think that there would not have to be an overhaul to healing. Making paladins a completely single target healer in a game that is all about aoe healing spam would kill the spec. As for going back to pre-cata, no thanks. Holy Light spam was mind numbingly boring.