With what lead time? The sequence of events would have been: (1) Nokia dies. (2) Devices already in the channels are cleared out at deep discounts (only way since there will be no upgrades, support, spare parts etc). (3) The media proclaims Windows Phone dead since nobody makes devices anymore. (4) Six months to a year later, the first Microsoft phones come out. Nobody even notices, since the platform has already been declared dead.