Why is it so necessary that Windows 9 be the next in the list? I mean, it's not a particularly standard list for user workstations: 3.1, 95, 98, ME, 2000, XP, Vista, 7, 8.
I can't seem to find the link again, but I think I read a Microsoft blog post somewhere saying that that name was already taken (by a Mr. Gates, circa 1985).
I heard that too but http://www.wikiwand.com/en/Windows_1.0 seriously? Who would mix that up? Also, given "One product family. One platform. One store" and the Xbox One they would have a cool One theme to build on.