Although I’m generally quite forgiving of Wizards – and I do like 4e – I’m astonished at the levels of stupidity involved in the GSL. I don’t think it’s all intentional. For instance, I really don’t expect they meant the license to meana later publication of theirs to make a bunch of previous products illegal due to unintentional name duplication. However, they should have. They really should have.
Someone on Paizo’s boards suggested that the license was really designed to only allow adventures to be written under the new system. Well, possibly. Unfortunately, by eliminating the ability to print the full stat-blocks of any monster or NPC that uses an ability from the core rulebooks, you really, really limit their usefulness.
Clark Peterson has said on EN World that he’s pretty sure that this license will kill dead his Tome of Horrors 4e (he’s doing a full colour Pathfinder version? Cool!)
To be able to put Clark off-side with you is inventing new levels of stupidity that are beyond the dreams of wordsmiths in coming up with new terms to describe them!
Ultimately, 3rd party publishers don’t make that much difference to my gaming habits. I tend to stick mostly with Wizards material. However, the license is disappointing… and very risky to use.