I've not been following Seth Godin's blog for very long, and despite it's apparent focus really not appearing to align well with my interests on the surface, I've found him to be very interesting to read (I'm sure you were already well aware of this). This particular post I think hit the nail on the head.
His opening point is absolutely right. We're all a little too often a little too ready to presume the fundamental obviousness of our own points of view.
The problem, to my mind, though isn't the disagreement. I think we all need to be able to accept our disagreements, enjoy them even. I think the real problem is not being able to agree to disagree.