If this release comes up as well as say the Canon EF 16-35mm f/4L in terms of sharpness improvements this might be one for me.
I have never owned the current 24-105, but I am thinking it might be a good choice for me over the 24-70II if the image quality is close and it focus's as quickly. Now that I have the 5D4 and with it's much improved high ISO (especially as I haw been using the 7dII for sport stuff ), it means I could get the shutter speed up to compensate for that stop difference from f2.8 to f4.0, and be at f4 which makes life a bit easier.
Plus have a lens that has IS and a slightly more useful focal range. I find with the 24-70 I often want that bit more reach.
The only thing missing in the equation is bokeh, but I am thinking I could get a nice prime with the price difference. Also If i get this I'll keep my old 24-70 2.8 v1. It's a nice lens IMO.

