"On the desktop, application windows will disappear for full screen display and context navigation menus".

This is my prediction. My daily use of smartphones, tablets and desktops shows me a big difference between devices. On the Desktop you work with windows, while on the other devices windows don't exist.

When I browse the web with Firefox on mu PC I often switch to "Full Screen" and in order to access the browser functions I need to go back to normal. I believe in the future, context menus will come in the middle of the screen, making it unnesseray to look for the window frame, just like when you go full-screen on youtube you can move in the movie or when you touch your smartphone.

The next question is than : how to dipslay multiple applications at the same time ?

On Smartphones, this is mainly solved by the use of widgets that you can drop on your main view(s)...