So as for GL 3.1 what can we expect? My predictions (/wild speculation),
(1.) Some time 2009, perhaps late Q1?
(2.) Working NVidia, and ATI GL3 drivers. Apple perhaps with Snow Leopard in January (10.6 going to have OpenCL right?). Intel perhaps not because of Larrabee not being out yet.
(3.) Geometry shaders, texture buffer objects, and instancing extensions get rolled into the core spec.
(4.) Uniform (parameter) buffer objects as an extension. Question as to if this functionality gets supported on older hardware which need to patch shaders after uniform changes.
(5.) Unlikely, but perhaps something to do with texture fetch from multisample textures. Maybe only a vendor extension.
Other things I would personally like to see in GL.
(1.) Roll in fence support (NV_fence/APPLE_fence) into the core spec.
(2.) Support for fences to be shared across contexts!
(3.) Would be nice to have support for keeping a buffer mapped with MapBufferRange( .. MAP_UNSYNCHRONIZED_BIT .. ) mapped during drawing. So one could keep filling in dynamic VBO ring buffers from other threads easily.
(4.) Would be nice to have support for MapBufferRange( .. MAP_UNSYNCHRONIZED_BIT + MAP READ BIT .. ) with the same functionality of being mapped during drawing. Combined this in the form of a readback ring buffer, with shared context fences and transform feedback, then GPU readback could become a lot more useful.