For those of you that keep your ArcGIS maintenance current, the ArcGIS 10.5 pre-release is available for you to download from your ESRI account. This includes ArcGIS Desktop, ArcGIS Enterprise, and ArcGIS Engine.
Note that existing ArcGIS 10.1-10.4.1 authorization numbers will continue to work with ArcGIS Desktop and ArcGIS Engine 10.5. At 10.5, ArcGIS Server is renamed to ArcGIS Enterprise. ArcGIS Enterprise requires ArcGIS 10.5 authorization numbers. When upgrading to 10.5, you will need to reauthorize for use.
ArcGIS Pro 1.4 is currently in alpha and continues to build towards functional equivalency with ArcMap while bringing its own innovations to desktop GIS and providing greater support for Web GIS. It features an improved and innovative user experience for processing and analyzing imagery; a new, secure, cross-platform scripting language for rendering and labeling; and greater capabilities for creating and using vector tiles. For those of you that have current ArcGIS maintenance, your account manager should have email from ESRI on how to participate in the alpha software testing program.