I would think the author's date to be a little too soon, although not impossible, but it may be released sooner than we may think. MS may be moving quickly on builds given that they have greatly changed direction with 8. They may throw all they have at it attempting to succeed.
8 to me seems to be more than just an OS, although I realize that's what it is. It seems to be more of a "personal social" launching platform with it's new Modern/Metro UI and apps. Does that make sense? It's difficult for me to describe. But if I may.....
We have reached the crossroads of computing within our modern age. The Internet (cloud), touch, mobility, and social interaction. MS with 8 (and Surfaces) and others are attempting to fulfill this market demand with the combination of all four segments. It has gone way beyond sitting behind our desktop PCs. Societies are desiring more to be mobile with smaller devices. A percentage of enterprise may adapt this as well.
Mobile devices demand less peripherals for ease of mobility. That's what the pads, phones, and hybrids (Surfaces) with touch UI fulfill. One needs to personally organize a launching platform, so that's what the Start Screen fulfills. One needs to synchronize devices, so that's what the cloud fulfills. One needs to socialize, that's what the Modern/Metro apps fulfill.
I think it to be rather ingenious of what MS is attempting to accomplish. An OS to run across multiple devices in conjunction with Windows phone 8. It will most certainly simplify computing. I think it to be one better than their competition.
Now we come to the gripes and complaints of enterprise and power users that need to sit behind their work stations for work to create. 7 will satisfy for quite a long time, but it's inevitable it won't last forever. Although the desktop remains for now, I see it disappearing sooner or later. We see signs of this in the leaked Blue build. More of the Win32 desktop is being moved to the Modern/Metro side. Perhaps they'll crank out 9 faster than we think to satisfy this market segment.
Let's not forget what we read that custom apps may be easily written to match a company's needs. This I would think to be appealing to businesses.
I'm sure MS does studies on builds as to what would be more economically feasible. Would an expeditious investment in a 9 for sale and profit to satisfy needs be more cost efficient than supporting those that upgrade (XP mostly I'd guess) or stick with 7 in the long run? If they could get 9 to be more appealing for sale, that may be the case. I would think we have to consider the economics of it, for after all they spend big bucks supporting OSs.
It'll surely be interesting to watch it all unfold.
