What David (and Keith Packard) has been baking for GLAMOR is OpenGL core profile support. With today's eight patches that were published is supporrt for GLAMOR in ephyr/EGL/XWayland for making use of an OpenGL core profile context.
The work involves adding VBO support to GLAMOR Xv, using vertex arrays, using GL_RED over GL_ALPHA, and other changes. This will allow GLAMOR to ask for an OpenGL (v3.3) core profile context rather than a generic OpenGL 3.0 context while retaining support for the non-core context but does break the ABI.
More details via this patch series. This work will most probably land in time for the X.Org Server 1.19 release due out later this year.