Today Microsoft shows a first look on Windows 10. Surprise. Surprise. They call it Windows 10.
Here you can read a blog post by Mary Jo Foley: ZDNet
All about the Windows 10 event on the Microsoft News Center: Microsoft unveils the future of Windows.
Windows for Business: Introducing Windows 10 for Business
Server & Cloud Blog: An early look at the future of the datacenter from Microsoft
ConfigMgr Team Blog: Windows 10 enterprise management with system Center Configuration Manager and Intune
Building Apps for Windows: Universal Windows apps get better with Windows 10
And the Technical Preview of Windows 10 you can download here.