How about a pie menu that starts, and is based in a corner instead of centrally on the screen? It would be more consistent with the pie menu idea, keep the media-up-front concept, take up less space, and would be easier (of sorts) to navigate because the boundaries of the viewable screen are clearly and consistently defined (the edges of the screen). Also, being that every screen on the planet has four corners, this could give way to specific button arrays the perform specific functions, such as top left = media, top right = automation, bottom left = computing and internet, bottom left = technical. You could even use compass directions to get more use out of the screen (top, left, right, bottom). The only issue is that a pie menu doesn't give much room for text, and would be very icon-heavy to be useful.
To think of it, another perk could be the ability to call up these menus without a touchscreen, such as a phone using its dial pad to navigate. The same numbers could be reused for successive sub-menus because each menu layer would function as its own ?entity? (I don't know how to fully describe that one... please forgive me). It would function much like dialing a normal phone number. In order to go back to a parent sub-menu, a 'back' protocol can be used ('Last' or 'Back' or even '8' on a remote control or phone, left arrow on a keyboard, right click on a gyro mouse, etc. TPs would be able to initialize parent menus from sub-menus directly because they would still be visible.)
For OSDs that use gyro mouse functions, when you hover over a function, its text description can show in a status display, as well as its corresponding dial-in number for use with a remote of cellphone.
I may be barking up the wrong tree, but I was just thinking over the pie menu idea and was inspired by the application's screenshot. I do think it can work, but there would need to be some rules in place for it to be practical.
I'll be posting some graphics on what I have in mind in a few hours, don't worry.