There is no 'one OS to rule them all', and the Maemo crowd (esp t.m.o. ) is not really whom WP7 is aimed at, i.e. there will be Maemites who will always prefer some linux variant (whether that be a future MeeGo, webOS or (gasp) Android device), and then there are those who would actually rather go to WP7 from Symbian or whatever they are using now.