I just got my phone yesterday Jan, 15th. and I tried the 3/19/13 method.  At first, it showed an update available on the notification screen; however, its only for the nagivation app.  SUCK!!!  Then I try to keep rolling the date on day by day and save to see it will work.  After rolled couple days it won't work so I just roll to April then save.  And try to check for update.  Now it WORKS!!!  It's downloading now!!!   

Hope it works on your end.