The document summarizes the current state of on-premises Exchange Server and its future direction. It notes that Exchange Server 2013 is almost 4 years old with limited new features, and Exchange Server 2016 adds some new features but still depends on syncing with Exchange Online. Long term, the cloud is Microsoft's focus for Exchange development, and it is unclear how many more major on-premises Exchange releases there will be before it is no longer attractive for Microsoft to maintain a separate codebase.