David Airlie's presentation at the Linux Australia conference was on "teaching the X Server new tricks." The talk mainly covered his recent work on PRIME / RandR 1.4 with GPU hot-plugging and GPU offloading and then more recently with Reverse PRIME. The work is mostly centered around supporting multi-GPU systems better in X.Org with systems like NVIDIA Optimus laptops or the increasingly popular USB-based DisplayLink devices.
As a future project, Airlie still talks about GPU switching support for the X.Org Server but that remains a difficult situation due to needing to re-initialize the compositor cleanly on switching graphics processors. Another future item is Post-Xinerama/Shatter for breaking up rendering between GPUs.
David Airlie's presentation is embedded below. The rest of the Linux.Conf.Au 2013 videos can be found from this Linux.org.au directory.