Hot thread! I a member of the IE team at MS and just came back from Future Insights in Las Vegas. If there is one take away is that it is natural and efficient to develop experiences that work beautifully across browsers, devices, and overcome any accessibility barrier: after all we want our content to be seen at its best by the highest number of people. 
Fortunately – thanks to the emerging tools, libraries and best practices - it is becoming easier and more efficient for front end developers to do so. I remember a similar case that surfaced on the tech memes a few weeks back, and I loved the rebuttal from Sean Gerety. http://techcrunch.com/2012/04/16/4ormat-rebuttal/ I think it applies very well to this case too.