Problem with 1080p emulators and GraphicsDevice.Viewport

If I use the 1080p emulators(5.5 inch and 6 inch) in Visual Studio 2013 to test my Windows Phone game, then GraphicsDevice.Viewport has the following values:

GraphicsDevice.Viewport.Width = 1279 pixel
GraphicsDevice.Viewport.Height = 720 pixel

Why is GraphicsDevice.Viewport not 1920 pixel wide and 1080 pixel tall? 1080p should be 1920x1080 and not 1279x720.

Is that a MonoGame bug or why does GraphicsDevice.Viewport has the wrong values?

Random thing I found on google:

Possibly related discussion:

And this sort of suggests it works :-/
http://developer.nokia.com/community/wiki/UI_Framework_for_XNA_and_MonoGame_with_high_DPI_support

1080p is sadly just a scaled up 720p. See:
http://msdn.microsoft.com/en-us/library/windowsphone/develop/jj206974(v=vs.105).aspx

Even detecting it is hard (you can use DeviceExtendedProperties AFAIK):
“On a 1080p resolution screen, the ScaleFactor property will return 1.5, although a 2.25x scale is used internally by the OS.”