But technical arguments aside, I think there's a bigger story here. Microsoft is working not only to create a great product in IE9, but also to convince people that it's a great product. Who would have imagined two years ago that Microsoft would seriously re-enter the browser market with a fast, standards-compliant browser? And who would have imagined that Microsoft would so openly acknowledge that users' choice of browser matters?
This is a great success for Mozilla (and yes, also for Apple and Google). We've forced Microsoft to compete on our terms.