Windows Phone 8.1: The pathetic developpment

Programming Microsoft is simply pathetic ... The Work on Windows Phone 8 were finished in August 2012. We are at the end of 2013, so a total of 17 months. Assuming that Windows Phone 8.1 will be announced in April, Micrososft would have taken 20 months to develop an Update of its product.

How does Microsoft want to be competitive? --- How?