To be honest, it sounds like they entirely gutted anything worthwhile about the OGL. Of course they're trying to "spin" it nicely, but what I'm reading is basically that, now, the new OGL/SRD will amount to the ability to create plug-in content (modules, new feats) for D&D and D&D only, but not IMPROVE upon the system nor utilize it for the construction of any other genre games. The ability to use d20 for every genre and style of game I played was the largest draw of the whole kit and kaboodle, for myself.
That, additionally, their spin cast gentle dispersion upon authors who utilized the former incarnation of the SRD to fashion these games is unfortunate.
The ability to rewrite the game from the ground up to create something similar to the game has always been available, by the very nature of the thing. I wouldn't try to fly that as a magnanimous gesture. That would be something akin to Microsoft releasing a press announcement that Windows was "joining the open source movement" by allowing the population at large to write 'computer operating systems' and selling developers a copy of Windows to look at for ideas while doing so, while warning the devs not to infringe upon any of their IP.
--fje