Most users are now running the kernel mode-setting (KMS) support found within the Radeon DRM driver for the past few years and new hardware these days is only being enabled under the open-source Radeon Linux driver using KMS. Even the latest enterprise Linux distributions with their latest versions are using KMS graphics drivers, and with Red Hat they even have plans to ship only KMS-enabled graphics drivers. With not many people using the Radeon UMS support, developers are now planning to kill off this old support.
This news doesn't come as too much of a surprise considering that Intel and Nouveau have killed off their non-KMS support long ago and that KMS graphics drivers are the future on Linux. Of course, now this just puts additional pressure on BSD developers to get their KMS port working well for Radeon hardware...
David Airlie wrote on the mailing list, "I'm seriously thinking of resurrecting the kms killing branch, can anyone give me a reason not too, we'd fork the current master into a UMS branch and move on."
Alex Deucher of AMD expressed his support of the UMS killing and Michel Dänzer (also AMD) agreed too.
The plan is to make the Radeon driver KMS-only for the xf86-video-ati-7.0.0 release.