Considering the 6D was considered the 'low light entry full frame', it will be interesting if they continue that trend with the 6D2.
The 5D4 AF points can do -3EV and -4EV in LV, so I wonder if the center point on the 6D could be -4EV to follow that pattern. It really needs at least 30 AF points, with at least half being cross type. The further most AF points on my 6D can be quite inaccurate so that's something they need to fix. Other features I'd like are:
1/8000 sec max shutter
1/200th at least for flash sync speed, 1/250th would be preferable (but doubtful since 5D4 is only 1/200th)
Tilty touch screen
WB button
Exposure compensation in M when using auto ISO
Focus Peaking in LV
Dual Pixel RAW depends on how useful it actually is, we'll have to wait and see
For the sensor, 24 would be great but I certainly wouldn't mind 28-30. It is more than likely wrong, but if the 6D did to upmarket what if it was 36-40MP? We have the 1DXII at 20mp, then next level down is 5D4 at 30MP so why not 6D2 at 40MP?
The 5D4 announcement has made me very impatient, I can't wait to even see new rumors about what the 6D2 will offer.