The latest news update from the middle of September on the AMD GPU FreeBSD Wiki is that there's a video BIOS mapping bug that's being addressed, suspend/resume support is slowly but surely getting into a working state, and there's a new AMD Radeon KMS Git branch.
The features of this new AMD Radeon KMS code branch is for providing multiple graphics card support on FreeBSD -- DRM drivers communicating with multiple GPUs either for display or render purposes. This branch also has setmaster/dropmaster support to allow for multiple X.Org Servers to run concurrently.
The code that this FreeBSD AMD code is being based upon is still derived from around the Linux 3.8 kernel with some TTM memory management bits from Linux 3.9.
The news update on the Wiki ended with, "We're now much closer but there's still a long way to go."
This initial AMD Radeon KMS driver support will be present in FreeBSD 10, which is currently in an alpha state, while Intel KMS/DRM support has been present since FreeBSD 9.1.