At first glance Agent 47 looks just like we remember, but if you look a little closer at his face he seems to have aged a little bit, he looks weathered, maybe even 'too old for this s**t'.
Bruce Willis references aside there's a few very subtle facial movements such as the slightest flaring of the nostrils and dipping of the eyebrows. According to IO this level of detail is afforded by the new Glacier 2 engine powering Absolution. It might not seem like much but these subtle touches could be put to good use in characterisation.
Chicago's finest are on the hunt for our dome-headed hero but they'll have some trouble since he's picked up some new moves over the last few years. In the video he can be seen dropping down from a ledge into a pool of darkness.
During his absence Agent 47 has seemed to have picked up a fondness for taking cover, which will no doubt rub a few Hitman purists the wrong way. He sticks to edge of the low balcony, adhering to its curvature as he moves along it. IO has said the 'sticky' aspect of the cover mechanic is an optional feature, and they've established a sensible middle ground by making Agent 47 crouch down below cover height regardless.
A little bit of sneaking later and Agent 47 finds himself making a poor decision and taking refuge behind a mostly empty bookshelf. Here he reaches into his box of fresh tricks and pulls out a mode called 'Instinct', which functions like a mix between Batman's Detective Mode and Eagle Vision from the Assassin's Creed games.
On this occasion guards in the immediate vicinity glow bright red and are visible through the walls, the path they'll walk while investigating disturbances is also plotted out and represented by a thick red line. The aforementioned purists will no doubt be mumbling words of disapproval under their breaths again so we'll take a moment to point out that IO has said the new mode won't dumb down the Hitman experience and that it "gives you more improvisation than you might think".
While sneaking around an on-screen indicator briefly appears, narrowing to a point as Agent 47 approaches a few patrolling officers. Our guess it's a threat level or line of sight indicator.
The stealth assassin tinkers with a fuse-box, causing the lights to flicker momentarily before a shroud of darkness descends. 47 uses the opening left by a bumbling guard sent to investigate to shuffle into the next room.