@DCMonkey: You don't always go to the start screen when you log in. Plus I think the function is a bit different - the start screen tiles are more like "all the newest stuff" and the lock screen is more like "all the stuff since the last time I was at the computer that I really care about".

And jeez, the argument about what is or isn't the start menu is one of the most preposterous parodies of programmer pedantry I've seen in a while.