My predictions:
Many larger 3PPs are going to shy away from the OGL and move towards ORC unless we get a test case with a court ruling that Wizards cannot de-authorize OGL 1.0a. Understandably, most are reluctant to put themselves in a position where they'll be that test case.
Some people will happily fill that gap and become OGL 2.0 content producers for OneD&D. This will likely ensure there's no real lack of 3PP content for OneD&D, but it is unlikely we will see anywhere near as many entire D&D SRD-based third party games as we do now.
Some companies will feel that making their game ORC-licensed will be a good PR move, and will do so. There will be a growth in the number of complete rulesets based on non-D&D SRDs. Likely, too much growth because of the percentage of players that want a D&D-alike.
At least for a while, there will be a rush of 3PPs big and small eager to be among the first names people see with ORC-licensed material.
Paizo ORC-ifys PF2. I have no confidence at all in predicting what happens there. Everything might go fine, and that becomes the basis for future D&D-alike rulesets. WotC might take them to court over the similarities to D&D, and may possibly win. Or lose. Or they might do absolutely nothing. There are far too many variables involved, including whether Paizo are thorough enough to remove absolutely every copyrightable trace of WotC's SRD, considering that the final judgement will be based on a Judge's opinion of similarities and is somewhat difficult to define solidly.
We will see more new rulesets than ever as established companies that have depended on the OGL decide not to risk either it or ORC-licensed SRDs, and feel their own ruleset will be the safest option of all.
All in all, quite possibly a far better future for RPGs in general and all because of the OGL mess.