I haven’t talked much about this, but Bob Zimmerman has thoughts.
I’ve been working on this behind the scenes for a couple years, in both DC and London, and some of the ideas in the accords may be based on my IAC paper from last fall, but these are much more limited than my proposals there. They don’t really “supercede” the OST; the administration’s position is that they are not in violation of it, and that it is “permissive” in that regard.
I don’t like the idea of countries on earth claiming sovereignty over off-earth property. Let people who go out there create their own governments if they want but existing governments have enough power.