Well, my favorite has to be grabbing an NPC and hitting alt-fire to break their neck with the other hand, I found that one quite by accident. Another one though, at least I think this happened, was that I apparently disarmed a CELL soldier.

I ran up to him while stealthed to grab him, and hit (F) to grab at him, usually I kinda mash it till I have them in my hands, but just hit it once this time. Well, sure as hell I had his SCARAB in my hands and he was reaching for his sidearm as I realized what happened. Is this actually possible or am I imagining things? I saw no other weapons on the ground that I might have accidentally picked up, and I apparently threw my SCAR somewhere behind him when I took his gun (I had to go find it because I prefer it to the SCARAB). Anyone else able to confirm this?

I did see the disarm in a trailer.
Unfortunatly I have to wait untill my PC is repaired.

if this is true it will be awesome!