http://www.eurogamer.net/articles/digitalfoundry-2016-gears-of-war-4-pc-exclusive-features-revealed
More details in the link.
Edit: Beaten! Mods, feel free to lock the thread.
Rayner also listed "a few items of note" the team are adding to the PC version. In his own words:
Dynamic resolution support (any resolution will be supported with a sensible dynamic field of view - including ultra-wide).
Increased texture resolution (up to 4K resolution for select texture groups).
A benchmark mode.
Full keyboard/mouse input remapping (including cover/run and roll split).
Far more comprehensive video settings.
More details in the link.
Edit: Beaten! Mods, feel free to lock the thread.