Several articles note that new attributes of the new operating system will be previewed on September 30, 2014

http://www.computerworld.com/article/2683914/microsoft-sets-windows-9-reveal-for-sept-30.html

QUOTE:  Microsoft issued invitations on Monday for a Sept. 30 event where it will unveil the next version of Windows, according to multiple online reports.  The San Francisco press conference will introduce the next iteration of Microsoft’s venerable Windows operating system. Most pundits and analysts expect the OS to be dubbed “Windows 9,” with the company sticking with the numerical moniker of the 2012 predecessor. It has also been known by the code name “Threshold.”

Presumably set for release in the first half of 2015, Windows 9, may be either the last major release of the operating system or the first in a string of smaller, less-ambitious updates as Microsoft accelerates its already too-fast-for-enterprise release schedule.  A revamped Start menu — one that hews more closely to the one in Windows 7 — a de-emphasis of the touch-first “Modern,” née “Metro,” mode and UI (user interface), and the ability to run Modern apps in Windows on the classic desktop have been bandied as Windows 9’s most obvious changes.

The mention of “enterprise” in Microsoft’s invitation bolsters the speculation that Windows 9 will be primarily aimed at business and corporate customers, who have spurned Windows 8 because of its split-UI personality. That, in turn, argues for a surfacing of new features and other changes that make the OS easier to operate and navigate with mouse and keyboard, still the primary input methods for business PCs.

It’s important for Microsoft to make Windows 9 attractive to those customers, Gartner analysts have said, if Microsoft is to convince them to move beyond Windows 7 — which has a lock on the corporate market — in time to avoid a repeat of the Windows XP longevity problem.