This article highlights four major new features for this new version for Windows currently in development 

http://searchenterprisedesktop.techtarget.com/tip/Comparing-Windows-10-features-with-those-in-earlier-OSes

QUOTE: The Windows 10 Technical Preview has now been out for a few months, and we can soon expect an updated build of Microsoft’s flagship operating system. What can longtime Windows users expect? Let’s look at some of the most interesting desktop- and enterprise-oriented Windows 10 features that users coming from Windows 7 and Windows 8.1 will immediately notice and enjoy.

1. New Spartan web browser – This may complement or even replace Internet Explorer in the future, with voice activation commands & embedded sub-browser modes

2. Cortana Voice activation system¬†– Microsoft’s version of Siri is expected to make it into Windows 10, giving users the ability to control their computer, ask questions, conduct Web searches, set appointments and other reminders, and more by simply talking in a natural voice to their machine.

3. Classic Start menu returns – to provide a logical, non-full-screen place to launch applications and execute searches. Perhaps most importantly, users will go to the Start menu to log off and turn off their PCs

4. Continuum Device Unification Рshifts the user interface based on what type of device the user is currently running.  When Keyboard is enabled, windows desktop mode is invoked, but when disconnected the device switches to Modern tile interface mode