There is mutual exclusivity. You cannot publish new 4th edition content under the new license and also continue to publish, print or distribute or make available for download (we're guessing) D20/OGL content for D&D 3. You also cannot fence sit. For example, you cannot publish a book with both 3rd edition and 4th edition content, nor can you publish two books with two different versions. Once you go 4th, you can't go back. Publishers can finish up their products in the pipeline and put out 3rd edition D20/OGL content for as long as they like, but once they publish a 4th edition product, they can't return to 3rd and the fate of their 3.x books are in doubt.
The end result? Publishers like Green Ronin and Mongoose are not likely to give up their profitable 3.x OGL products for the opportunity to try 4. Green Ronin's big game is Mutants and Masterminds, a brilliant extension of the OGL license. Mongoose's most popular RPG is Conan, also using the OGL license (and now not printed by monkeys).
The Paizo/Necromancer team up is pretty ideal, with Necromancer committed to 4th edition and Paizo committed to Pathfinder (3.5 OGL) and supporting Necromancer's D&D 4 efforts. Paizo would not be allowed to publish a 4th edition product and still go back to Pathfinder. The head of Necromancer Games, Clark Peterson, has been providing a lot of clarification and some details of his discussions with Wizards, since they have such a unique situation.
Small publishers would be forced to choose and thus focus on the new or the old. That could be a good thing. Creating a clever spin-off company to support one version or the other is specifically dealt with in the license. Publishers that are moving to 4, won't be able to continue producing re-prints of existing D20/OGL material either. Those that publish 3.x material are being required to remove the D20 logo by the end of the year, if they want to produce GSL materials. There's also no reason to believe this won't apply to PDF versions of products.
From a store owner perspective, I see a few things:
- Who cares? About 20% of my D20 sales are third party, roughly the percentage of people who care about third party publishing on Enworld. 80% of D&D players won't miss them.
- 3.5 Support. Those who were hoping to ride the long tail of 3.5 will find that tail a little shorter now. We'll still see used books and PDF products from a myriad of publishers, but any publisher who moves forward will be yanking their 3.x PDF products.
- Diversity. I've mentioned before, the vast array of products is difficult to manage, but it's what keeps my store different from Barnes & Noble. This solution will provide some diversity, without the wholesale printing of new D&D 4 products by everyone with Microsoft Word and access to Kinkos.
- Dumping. There will likely be an industry wide move to dump all the D20 back stock by the end of the year. Anyone with plans to produce a 4th Edition product will need to liquidate their old 3.x inventory. In the past, I would jump on this stuff, and I've done very well with buying liquidated 3.0 inventory. However, I'm not so keen to do this again. We've seen the twilight of 3.x for close to 18 months now and the market is pretty well saturated.
- Quality. There is an argument that focusing companies on either moving forward to 4th edition or staying with their successful OGL products will make the marketplace better. Requiring them to do it is certainly controversial. One argument against this is that veteran publishers, dependent on their 3.x income, won't be moving forward as quickly. This means the marketplace is open to new, inexperienced publishers, potentially creating the same problems we saw when 3.0 was released.