Without getting into a whole lot of stuff that's gone on in this thread, I fail to see what the GSL really offers. Say I write an adventure. I can give the names of the monsters in the MM, and even then, not the cool ones (drow, beholders, mind flayers, warforged, shadar-kai).
IF I wanted to say "This room has 4 orcs and 2 zombies in it" a bunch of times, do I need the GSL?
I can't say I blame Hasbro for wanting to be closed with everything, although I don't see what value they get out of it, either. I mean, if I'm going to put out a product with Hasbro's trade dress that says "Dungeons and Dragons" right on it, and it would be better if it had things like monster statistics and abilities printed in it, well, who really looks bad? If the goal of 4E is to attract the non-gaming, manga, anne rice, and ultimate marvel crowd... won't disappointing 3pp reflect poorly on Hasbro and their IP? Under the OGL, if Mongoose or Malhavoc put out a bad product (and I'm just picking on them because they popped into my head after reading all this, I don't mean any slight), then it reflects poorly on them. If said bad product has "dungeons & dragons" on the cover and is internally visually identical to Hasbro 1st party products... that reflects poorly on the brand as a whole.