1: Landmark locations like the Louvre,Gugenheim or the Vatican. Just to add some gravitas.
2: Newspaper post heist screen. Like earlier Hitman games, i think it would be cool to read about your exploits in the paper.
3: The ability to tell hostage's to follow and wait. Same for computer AI during solo missions.
4: New skills for:
Technician- wire cam to slide under door or drill through wall.
Ghost- Can do certain interactions with mask off. Spray paint cameras and open doors.
And i forgot the rest.