David Airlie of Red Hat mentions during this discussion that he has a major overhaul coming to the X.Org Server video driver ABI, which would require significant changes to the DDX display drivers.
At the moment I have a large project in the works to redo the driver ABI, its pretty much an impossible project no matter what happens, its a major ABI change and will pretty much require major reworks off all the drivers.
Now I've no idea how to do this with the current model, even with the drivers merged its going to be a real pain to land, thats if I ever even get it to a useable stage.
The mailing list message appeared here.
We'll see if this "impossible project" materializes or what comes about. Lets hope that if any major video driver ABI breaks are coming, that AMD will be more prepared to support them in a timely manner, unlike their notorious support time right now for most major X.Org Server and Linux kernel revisions.