One of my minor complaints from Crysis was the aliens and not being so much fun to kill....aside from the Hunters (the giant 4 legged monstrosities). In Crysis 1 they were just no fun to kill, they were tough to point down sometimes due to how agile they were, but fighting them wasn't interesting. The Koreans were fun because their AI made them respond in unique and interesting ways while the aliens just felt rather single minded and you were not given nearly as many fun and creative ways to kill them.
Warhead remedied this a bit by making them work in packs, and they were more in your face and aggressive with a somewhat "holy shit!" factor when fighting them. The smaller guys had this more primal aspect of them from the way the traveled in packs and would lunge at you trying to tear you apart. They could be a whole lot better, but Warhead was heading in the right direction.
These new aliens look terrifying, powerful, and aggressive. They look like the ACTUAL aliens (most of what you fought were just drones, the real onces are the "swimmers" inside the ship) wearing power armor and given an unhealthy does of steroids. they looked like the aliens and cylons fused into one uber awesome enemy. It's too early to tell, but I do hope the new and awesome design isn't the only change. I want these things to be intelligent, mean, and use tactics that are both conventional and unorthodox.
So yea, I like the new design, and hopefully this means more fun to fight enemies.