OpenGL 2.0 suggestions
1.) Vertex shader can read from the texture.
2.) Vertex shader can read from the OpenGL allocated arrays.
3.) Tesselation Program. The set of comands is the same as one for the vertex shader plus 3 predefined functions:
gl_Begin(GLint);
gl_End(void);
gl_Vertex(void) or probably better gl_EjectVertex(void);
The output of the Tesselation Program can be stored as OpenGL Array Object.
4.) Programmable texture filters (filter is just a NxN matrix).
NEAREST_CONVOLUTION tex env mode.
5.) Hierarchical programmable tests for {depth buffer}, stencil and aux_datan.
I wrote the article about OpenGL 2.0.
The original version (in Russian): http://www.ixbt.com/video/opengl20.shtml
You can read the English translation: http://www.digit-life.com/articles/opengl20/index.html
PS. Please excuse my poor English.