Apple issued an update to their Pro Codecs today which looks like it includes a new version of Pro Res (4444 XQ).  I imagine we will start seeing this codec as an acquisition format in next-gen cameras and as a delivery requirement.

Here is what the Pro Res white paper has to say about it:

“Apple ProRes 4444 XQ: The highest-quality version of Apple ProRes for 4:4:4:4 image sources (including alpha channels), with a very high data rate to preserve the detail in high-dynamic-range imagery generated by today’s highest-quality digital image sensors. Apple ProRes 4444 XQ preserves dynamic ranges several times greater than the dynamic range of Rec. 709 imagery—even against the rigors of extreme visual effects processing, in which tone-scale blacks or highlights are stretched significantly. Like standard Apple ProRes 4444, this codec supports up to 12 bits per image channel and up to 16 bits for the alpha channel. Apple ProRes 4444 XQ features a target data rate of approximately 500 Mbps for 4:4:4 sources at 1920 x 1080 and 29.97 fps.

Note: Apple ProRes 4444 XQ requires OS X v10.8 (Mountain Lion) or later.”

Here is a link to the full document and a section on data rates for fun.