First, and foremost, New shooting mechanics - it is hardly ever fun to have a shoot out in this game.

A wall hug type manuver

The ability to quick kill without having the hold a melee weapon in the air and walk towards a target - Maybe the ability to break necks or choke with hands (only to incapacitate not kill) or body slam (This feature would be pretty awesome)

A new melee system - punching needs to be more satisfying, being able to string together a better combo could be helpful

More Weapons/Improving weapons - they feel underpowered, and aiming in awkward

A lock picking mini-game (maybe)

The ability to interrogate (Ala MGS and Splinter Cell)

FASTER reload times, man I died so many times reloading

An improved rag doll effect - The Hitman Series has a ridiculously overdone ragdoll effect.

Missions that are not set in the past

More opportunities to snipe

Maybe being able to customize weapons beyond just the ones they allow. Basically, allowing all weapons to be augmented to some degree.

New "Sneaking" mechanics - the one they used in the last game I was not fond of

This is all. Even with my list of suggestions I still think the Hitman series is one of the greatest ans I play every game.

clayron

Haha, every single time I die reloading. Another feature I would like to see is real explosives like a rocket launcher. I be psyched if they threw in a hand grendade. Smoke grenades would be cool too. Also make it more like Grand Theft Auto. For example to balance the explosives, they would call in tanks depending on the notoriety of the hit.