I will be waiting for the new bodies to be properly reviewed and tested before spending any of my money. The big item for me is the promise of improved AF. I'll wait for factual data and test reports. Everything sounds quite promising indeed, but I am not seeing test results as of yet.
Reducing the noise levels to allow increased low light capability from using even higher ISO is also a very good thing and is something I would gladly trade for increased MP. The ability to capture images previously unobtainable is worthwhile to me. The 18MP of the 7D are more than enough to allow rather large high quality prints to be made. If I wanted to produce larger files for even larger prints I would first question what I wanted them for, and if needed I would go buy a MF or LF system if that was required. The question to me is whether the bulk of the improvement we are seeing in JPEGs is from the sensor, which would carry over to the RAW files, or the firmware which may or may not process noise out of a RAW image. Again, I'll wait for factual data, sample pictures and test reports. The interplay of the hardware and software in creating JPEGs don't leave signs behind telling us how much either component improved, just the overall JPEG processing system.
Given that the new RT flash is capable of driving 5 channels, up from 3, I am also thinking that is another welcome perk to the 1Dx and 5Diii for portrait work.
Patiently waiting for the manuals to be made available for download to learn more about them.