i've spent some time thinking about this, and came up with something similar.
For the consumer market only:
imagine an ipod nano(6th gen, the square clip-on thingy) device with non volatile ram(next gen memristor) say 1Tb, lowpower quad core, and wireless connectivity all the size of a silver dollar. This would store all your media(music, pics, movie), contacts, os preferences and settings, your applications, bookmarks, and mailclient/texts. The thing would function as a mini file serve/pda/cell/gps that sits in your pocket, or on your wrist like a watch, or on a chain around your neck.
It would broadcast the display buffer to an interface of your choice: jawbone type hands-free if all you want is phone; small tablet if you like hand helds, notebook size thin client if you want mobile productivity, etc. The interface would be essentially dumb, no permanent storage, it just receives the display buffer and takes user interface inputs(keypress, finger swipe, stylus tap). The interface would be more or less disposable, such that if it is lost or stolen, all the important stuff (your data) would still be in your pocket.
This personal token pc, would sync and backup to your home hub. The home hub would be a personal server that handled update-downloads, media stream, torrents, mail serve, smart home and appliances, and render/encode/cpu farm. If you only need basic services you pop in a cpu with standard low power core + 4 general purpose heavy duty cores. If you work or game, you get a cpu with default low power + 32 cores (or more as required). Everything in your house would be a thin display that went through your pocket token and relayed to your hub. Your workstation would read the apps on the token and run it on the hub cores. The games stored on your token would play on your 50" display and run on the same hub cores. When you went to your friends house, you could play your games on his hub cores.
The idea is to eliminate all the redundant cpus, storage drives, duplicate aps, os. Everything stays in one device and it can connect to other procs when it needs more computing horsepower. No more downloading the same windows update 3 times if you have a 2 desktops and a laptop. No more buying multiple copies of the OS.