According to the information available from Microsoft Exchange Team, the on-premises release is planned to ship in the second half of this year (2015). As always, they convey the message that there are new features, enhancements, and refinements that add up to goodness on the way for end users, IT, and your organization as a whole. From the blog, some of the highlights of the new versions are,
It is also unveiled that, some of these features are already birthed in the cloud, office 365 platform. Lets wait to see the enhancement that MS always committed to deliver.
I will try to grab information and share it with you all as and when it becomes available.