Paulo Zanoni of Intel's Open-Source Technology Center sent out a set of 30 patches on Wednesday. "I've been working on this patch series for some time, and even though it's not 100% bug free yet, I feel it's ready to get some feedback, so I'm sending it as an RFC. The ultimate goal is to make clocking+HDMI+DP+eDP work flawlessly and without hanging the machine."
The patches allow HDMI to work but multiple displays over HDMI isn't fully baked, DisplayPort and embedded DisplayPort (eDP) support is maturing, and other mode-setting handling too.
Those wanting to poke through these display patches for Intel's 2013 Haswell platform can find them on the intel-gfx list.