Please note one thing. WP 6.5 and WP 7 possibly don't share a single line of code. They are totally different OS. (it's not only an UI revamp, even if the UI are on different planets). It doesn't make any sense to look at their aggregated market share. What happens when looking at separate numbers? - 6.5 is free falling like Symbian. - WP7 got from zero to 2% market share in one year. Indeed, this is comparable to Android's beginning.