What all these "inventions" neglect to (or choose to not) consider is that this general idea of a portable computer, "with you all the time" is NOT constrained by the computer itself (heck, you're already carrying an equivalent of that gizmo in your phone) but by the availability of decent peripherals. Sure, ultimately the phone is capable of functioning as a self-contained computer, but it's definitely not convenient to use as one, as-is. You'd want a full-size mouse, keyboard and screen to go with it - and just arbitrarily providing one of them (the mouse, here) will not solve the lack of the other two, even if ads for such gadgets try their best to convince you spare screens and keyboards are ubiquitous. The truth is, we're peripheral-limited and that's unlikely to change as long as working on a full-sized desktop or even laptop will remain much more comfortable than on any ultra-portable solution.
To be honest, the most ubiquitous peripheral today is... another complete computer - which is why solutions like the obscure, now defunct "Black Dog" USB dongle (that essentially cannibalized its host PC for its peripherals, but ran all software locally, outside its host, using it only as an x-server) still seems the best idea of the bunch. It's a shame it didn't take off. Maybe this would be a good time to re-implement the same thing in a smartphone? I mean, they already have the only required USB connector anyway...