Microsoft today announced the time frame in which we can expect the release of Windows Server and System Center this year. Microsoft revealed that they will release further previews of Windows Server through the remainder of 2015, with the final release in 2016. So, Microsoft has delayed the release to 2016 instead of the originally planned late 2015 release. Also, Microsoft confirmed that the next preview is planned for the spring of 2015.
Windows Server will continue to share the same core technology as Windows and we will continue working together on solutions for our customers. In fact, the next version of System Center Configuration Manager, which delivers support for Windows 10, will ship in a timeframe that aligns with Windows.