Edited: Sorry John I did not go back far enough in the posts to see yours. I did however include a link to the documentation.
Today Broadcom released register-level hardware documentation and the the full source of the OpenGL ES 1.1 and 2.0 driver stack for the Broadcom VideoCore
IV 3D in the BCM2835 application processor used by the Raspberry Pi.
You can download the hardware documentation and source code release here: http://www.broadcom.com/support/