@Matt Thomason
I think a lot of the discussion around this issue, and around ORC, seems to be driven by some confusion about the legal issues.
If X work is derivative of WotC's, then X is liable to a copyright infringement suit from WotC unless X has a licence. The only licence that seems relevant to me in this respect is the OGL v 1.0/1.0a.
If X's work is not derivative of WotC's, then the opinion of WotC about whether or not they have a licence with X, in respect of WotC's copyright, is irrelevant. X can publish away. And if X wants to licence their work to Y on the terms of the OGL, the only risk in doing that is that WotC might complain that X and Y are reproducing WotC's copyrighted licence text.
So the only reason for moving to ORC that I can see is to avoid reproducing WotC's copyrighted licence text. Whether that move is sensible depends on what the risks are of reproducing that text, compared to the costs of losing all the OGC under the OGL v 1.0a.
Hmm.
Lets say in this case I am Z. I have a work that is derivative of X,Y,
and W, licensed under all three via the OGL. I have a couple of paragraphs lifted directly from W's SRD, a class from a book by X, and a spell from a PDF by Y.
Now, I am assuming in this case I have three seperate OGL licencing arrangements here with three seperate originators for three original works (in addition to all the works they may have referenced in those works).
I am now concerned that while X and Y are happy with me, W may try and throw their considerable weight at me for the use of their copyrighted SRD material, of which my, X, and Y's work is all derivative.
I feel more confident in this instance deciding that from now on, I'm going to work with an SRD by another company (P) altogether, preferably under a license which is owned by a neutral party to reduce the risk of P attempting to unilaterally change the terms. I will no longer use material from X or Y, unless they release something under this new license, and wish to make no further business relationships with W at all because I no longer trust them to follow the terms of our previous agreement and would prefer to avoid it ever becoming a legal issue.
My move to ORC in this case is to avoid both W's copyrighted license text
and their SRD in future. I no longer wish anything in this new work to be derivative of W's. There's a pretty good chance that I will look for P to be a company that has an SRD that has no historical connection whatsoever to W's work, although I might investigate the possibility that P's SRD does have some historical connections but nothing copyrightable. Admittedly I feel more comfortable with the former, but if P is confident enough to go to court to defend it, I may consider the latter.
EDIT: Further to this is that I now consider W to be potentially hostile to my use of the license we agreed to. I do not want to fight this in court, and am far more comfortable working in relationships with companies that
want me to be in that relationship with me as opposed to one that appears to be making moves to push me out or a relationship it regrets making. If W doesn't want me on board, no matter what the legal status, that's going to be very uncomfortable from now on with them potentially watching for the slightest reason to push me away. No thanks, not willing to work like that.