We ought, I agree, to abandon the idea of 'differentiated instruction' (and critics of learning styles need a different target to hang their criticism on). As Tom Welch, cited here, says, "What we really need to help occur in classroom is differentiated "learning." This accomplishes the student ownership of the learning, allows for a passion-driven approach, shifts the responsibility for the learning to the learner (where it belongs) and changes the teacher's role to what you consistently advocate. There also also many other reasons -- like the elimination of the typical classroom culture of dependency, and the way this allows learning to go viral by removing artificial timelines that ignore individual learner needs, passions and differences." This is very much what we're up to with MOOCs, I would say.