What prevents the following scenario:
1) the majority of
3PP hops onto the
GSL, agreeing to abandon their
3E IP
2)
WotC terminates the
GSL in nine to twelve months time, as soon as the majority of
3E IP have been "upgraded"
3) D&D returns to being totally closed. Anyone trying to resurrect their
3E IP using the
OGL will be shot down according to the terms of the
GSL.
4) Hasbro creates a new division to handle D&D sales called Total Sales Restriction.