I just watched the Gamersyde version of the trailer frame by frame on my TV and just felt like mentioning a few of my observations. I played through Crysis 1 on Delta just last week and watched this after a session of 2 they're pretty fresh in my head for comparison.
First off, level design looks way more open than Crysis 2. If you look in the background of several of the areas as well as at the minimap you can see that there are many paths to get to the various encounter points. It looks like most times you can approach from any direction on the block and there are a lot more climbable, smaller buildings to add to the verticality. Ceph also seem to be patrolling similarly to the way the NK did in Crysis. Not as open as 1 but certainly closer to that than 2.
Second, there is a lot more detail than in Crysis 2. Textures are super sharp and have some of the most detail I've seen in a while. If you look at the background you can see that it visually looks a lot like Crysis 1, if it was in a denser jungle. The HUD, weapons, and aliens are the reasons it seems to look identical to 2 at a glance but the levels are far more similar to 1 in art direction. The particle effects are also a lot nicer. They're not as over exaggerated as the particle mod but they're a step up from 2.
Third, the standard guns (Scarab is in this trailer) are much lower on screen and angled out a bit farther than in 2. This really helps visibility. The reason the Ceph gun seems so big is that it's shoulder mounted and they seem to be going for a bigger visual differentiation between hip firing and shoulde firing.
Fourth, you can see some new Ceph and Ceph behavior. When Prophet picks up the Ceph Plasma gun he grabs it from the wreckage of a small Ceph mech. When he turns immediately after that you see what they look like functioning. They appear to be tiny versions of Pingers. When the Ceph tackles Prophet later on it actually knocks the gun out of his hand so I'm pretty sure that means that the Plasma gun is like the Swarmer and the HMG, a limited time carry only weapon that doesn't take up an inventory slot. The Ceph also follows up the charge with a few different attacks than it would in 2.
Finally, animation seems to be a lot better. Currently it uses the same basic animations as 2 but they're blended a lot smoother. Before there was always some weird judder, particularly when switching between weapons. That seems to be gone now.
Mostly minor stuff but I thought some of you guys might be interested. The editing of the trailer really makes it hard to see that it is fairly different than 2 in layout. Whoever edited that trailer really failed at showing the differences in level design. There are a few shots where things look dramatically more open than 2, yet they're only on screen for a few frames.