Over at the OpenGL.org Registry are the specifications for OpenGL 4.5 and GLSL 4.50. There's proper direct state access as part of an ARB extension, clip control, and other features. The full listing of new extensions to OpenGL 4.5 include:
Those hoping the Khronos Group would have introduced a major API overhaul or other groundbreaking changes will have to wait longer. The Khronos Group hasn't officially sent out their OpenGL 4.5 announcement yet but we assume will be doing so later today from SIGGRAPH 2014 in Vancouver.
Now to wonder how long until AMD and NVIDIA put out proprietary Linux driver updates to expose OpenGL 4.5 support... If the past is any indication, NVIDIA should be out almost immediately (today?) with an OpenGL 4.5 beta driver while it generally takes a bit longer for AMD Catalyst. In terms of the open-source Mesa support, they aren't even yet to OpenGL 4.0 so will still likely be a year or longer before seeing GL 4.5.
Update: There's already a beta NVIDIA OpenGL 4.5 driver available.