What I would like to have is a computer with many programmable circuits so that the system can reconfigure and rewire itself on the fly.
When you want a music player or a video player, or a video encoder, or whaterever, it loads the codexs onto very low power circuits and the main CPU idles as it only does enough to keep data fed between the memory, disk, screen, and the circuits. Imagine a computer that could play 1080P video while encoding the video at the same time in real time and only draw a few watts of power. Imagine being able to convert a half dozen videos at the same time, in less time than your most powerful computer can do it now, and still draw less than 10 watts.
A few dozen common protocols and functions could be permanently loaded into ASICs so that they are always ready to go without any setup time.
The computer could be upgraded by just replacing the ASICs with newer ones, or stacking more