I will avoid the "easy" joke that it's because so many sites balk at running properly under IE9 (oh... guess I didn't after all), and point out that I do believe that Microsoft understands they need to regain a certain amount of cred if they are going to regain the number 3 spot they need to be able to eventually take a shot at the summit again. I do think their development process gets in the way - in that they are setup not to be able to accept good ideas from the community that Firefox and to a lesser extent Chrome are able to. On the other hand, they have a better view of the corporate environment than the others, and I have to assume that will pay off at some point.