After thinking on this awhile, I'm thinking this must be a pretty big project if the speculation is true that it's 20 months away. Could it be a new OS code-named Blue, but named Windows 9 or another name? The last two were numbered, so I'm assuming it'll be 9. Who here knows the history and timeline on when they start to develop their next OS? I would think immediately?
I would imagine they have an idea of what direction they want to go in their overall business plan, especially with the big change of 8 along with the Surfaces. There must be much consideration of market demand/desire and user data they collect from past OSs. Technical advances in hardware also. I would think much discussion in many meetings of planning would be undertaken before any code is written. If so, how long would that take? It's mind boggling to me. They invest millions on develpement and marketing.
I think the Start Screen will stay, but with some improvements, such as tiles opening to or exploding to more "subtiles" like in a submenu as in the past. The Start Screen gets to get rather large otherwise. The idea of windowing Modern apps such as with ModernMix is something I think they will consider, for there is much complaint as to this. "After all, it is called Windows". But, then again they need to keep the desktop to perform this. Perhaps it'll be another type of " personalized multipane user screen" where one can open multiple apps there. It will be able to be saved for use again and again. Sort of like the old desktop, but within the Modern GUI.
The big question I have is whether or not the desktop will remain. I don't know enough about writing code to know whether or not all software can be written in the Modern interface within Window Store apps. Some say they can't, some say yes. If it can be, then I would think the desktop would go eventually. No need for it then.
Of course, a lot depends on market trends. How and what are people using to compute nowadays? Consumption and/or creating? It seems we don't want to sit behind our desktop PCs any longer, although it is still much needed in business. Desktop PCs have flatlined. More pads and cell phones being sold for sure. Societies are more mobile. Data is almost instantaneous with the speed of our infrastructure (including more free WiFi hotspots) and hardware. We don't need the "leash" of a wire as much. The internet is billions of pages big. A lot of information at hand. The Cloud is another item.
All in all, I would imagine there is much to consider when creating another OS. It must be exciting to be a part of it.
Those are some of my thoughts today. I hope I've added just a little to your original intent of your thread, Lee. Y'all have a good weekend!