Which significant 3PP has hitched their wagon to Pathfinder, aside from Paizo, who would have done so anyway, crappy GSL or not?
Game's not final yet and there's no 3PP license (although it's obviously OGL). I think that Adamant and Necromancer, at least, have expressed interest in Pathfinder support and Green Ronin may have alluded to it (although I could be inventing that in my memory).
If not for the GSL delay, there could well be no Pathfinder at all...