I've been working the past few hours trying to figure out why, all of a sudden, my Windows 8 app couldn't get past the splash screen. I did find one hit online that I was hoping would help, but my problem had nothing to do with Visual Studio acting up. As usual, when tearing things apart and trying to put them back together, I inadvertently missed adding a crucial line of code in the main page's OnLaunched event:
// Place the frame in the current Window and ensure that it is active
rootFrame.Navigate(typeof(Views.MainPage)) doesn't do the trick by itself.