The new X.org will be pushed to the [testing] repository in the next few hours. Xorg-server 1.4 comes with many core changes such as:
- a stable release of xf86-video-intel
- randr 1.2
- xorg.conf becomes partially obsolete
- an updated ABI for drivers
The ABI change breaks Nvidia's legacy drivers, so everyone using nvidia-96xx or nvidia-71xx should either wait until Nvidia fixes the issue or use xf86-video-nv in the meantime.
As usual, feel free to file bugs for all issues you can find.