You know, something just occurred to me.
You should make a new company to run the 4th edition licence, and keep the old company identity pure
OGL.
In fact, reading the
GSL... I see nothing right off that prevents the rights to a 4th edition setting being sold off to a 3.5 edition design company, and have them backward convert it.
Mind you, I'm not a lawyer, and just an evil minded person, but what's other's take on this?