OS's and their Shells

I've been thinking (which is probably a dangerous thing) about what an operating system could look like if you could just start from scratch.

What if you could just ignore the existence of the current interface paradigms and created something new? What could it look like?

The current windowed paradigm goes all the way back to the old Xerox prototypes and everyone has been copying and improving on the idea ever since Apple, Microsoft, Unix, Linux, and the list goes on. Just about all mainline operating systems today package the jumbles of compiled code in boxes and call them programs.

I suppose unique is what you have with Singularity; I don't think I have seen an operating system that looks like it before, though it is pretty much all command line with a Matrix like feel. It's cool but most of the coolness is hidden behind the shell.

A cool design I have played with a little around work it the Surface PC which lends it's self immediately to intuitive interface design.

So, if you could design an OS and it's shell, what would it look like? Would it be 2D, 3D, Command line… what?

Watching what is going on in HTML development it might not be long until we have 3D web. Could it be the next OS interface design?

Would you have a game shell with lots of fancy graphics and cool effects or would you have a "keep it simple silly" style to boost processing to things that don't render on the machine to make a work server?

Hollywood has tried time and time again but the shells that are designed for TV and Movies are ridiculous at best designed for flashy effects rather than actual use. But they do present new ideas from time to time.

I'm not sure what I would do. The possibilities are limitless. I think 3D should be a native API, but not sure how it should be used.

Anyway, food for thought.