Just one.. very morbid thought: does your tool require to be maintained as new GL versions and extensions are added? Is it possible to tweak as follows:
  1. Same nice command line options as now
  2. Takes as input a set of GL header files from which it generates the data. The idea is that glext.h (for example) has that functions for an extension foo are surrounded by #define GL_foo/#endif pair.

Though, I wonder about the horror of reused tokens and "dependent" extension functions (for example in an extension, "if GL_foo extension is supported then also the following functions for GL_bar are added: glBarFoo()" ).

At any rate, looking forward to futzing with this.