ES2 does not support the fixed function pipeline, so this enhancement will require a pure shader based mechanism.
Also as ES2 has disable several features they simply will not be able to work with this pipeline, for example QuadArray usage will simply throw an exception.
There will need to be significant documentation released with this enahncement, so that work should go into bug
Many, many examples of use and shader examples, in java3d-examples
I still need to produce a good guide to writing shaders, but what's in the example includes:
tex coord generation
texture + lighting
various material usages
information on fog data that's available
SimpleShaderAppearance.java and fixed_function_shader.vert and .frag
basically show everything that's needed to get shading done.
There is a nice comparison in the sphere_motion package of FFP, glsl with #version 100 built-in variables and the gl2es2pipeline equivalent, showing how similar it is.