I hope that in a few generations, Apple will make one that is all about lowering the weight. Let's say they can lower the weight from 650g to 350g by removing the metal enclosure, front glass, front display, and smaller components. I would buy that to be able to work on the go and it'd be an amazing piece of entertainment device.
Finally, I'd like to share what I'm viewing with friends and family such as a movie screen or a 3D model fixed in the same position.