It's a bit confusing.
First, it seems clear that one can create new types of kobolds, devils, demons, and so on. However, as I asked in my Devil&Demon thread (and still want an official response on), there seems to be some issue over what "redefining" means, and whether it applies to fluff. It seems that the most restrictive reading of the
GSL/
SRD is that I can neither create my own culture for kobolds (this would 'redefine' the term), nor can I take the fluff text for kobolds in the
MM and build upon it (as that would be referencing non-open content).
I'd like this clarified, as books of race/culture fluff are one of the things I most want to see coming out of the
GSL. I'm concerned because it seems as if making sure all
GSL products fit into the "assumed world" of D&D is one of the functions of the
GSL, and that would be Seriously Depressing.