Obviously Microsoft is taking a page out of Apple's book, but this is going to far. Micrsoft needs to recognize it's long-term strength has always been the open(ish)ness of their platform.

Hopefully they recognize the error of their ways and make the app store the best place to get apps, not the only one.

I don't necessarily have a problem with using IE, if IE10 is a decent browser, most people would have no reason to change as the numbers of IE6 has proven over time. If the majority of users aren't going to install another browser anyway, why lock down those who will?