If these rumored specs are accurate, this will be my next body.
Honestly, I just want a full-frame version of my 70D with the newest generation of sensors from Canon. I'm guessing it won't keep up with 70D frame rate of 7 FPS, and I prefer fully* articulating screen to tilt-only, but everything else will be enough for me to go for it.
Okay, to be really honest, if the 5DIV had a fully articulating touch screen, I would have figured out a way to scrimp, save and/or sell things to buy it.
* Fully articulating means it can be closed to protect it while in my bag. It also gives more flexibility in tight spaces or weird positions. Tilty would be better than fixed, but not nearly as useful as articulating...for me.