I really like the new designs. They seem to be taking a Valve-like approach, where enemy roles and abilities are implied by their physical appearance. Sectiods look like psionic-using glass cannons, and mutons look like something that you need heavier firepower to take down. Most of the tension in the original came from the gameplay mechanics rather than the graphics, and I think adjusting some of the designs to be closer to the gameplay while remaining true to the overall aesthetic is a good idea. I'm looking forward to seeing the snakemen and chrysalids.
I'm not sure how I feel about bestial Mutons. I think they'd look more Evil SEALs if they were less bestial. I like the tribal thing, that's cool, but as they are right now they look more like Halo's Brutes than highly-trained cold-blooded killers. I would have had them upright, seven feet tall, wearing non-bulky armor (both to allow room to move and to show the tattoos).
The original also made heavy note of the fact that each of the races was engineered (genetically and cybernetically) by the etherals with a specific purpose in mind. The gorilla-like frame emphasizes this, and the bulky armor gives them a reason to be so muscular as well as communicating to the player their resistance to low-power weapons.
I must admit that the music and art interviews seem spot-on. Although it likely won't be until close to release, I'd like to see if an interview with the gameplay developers will have a similar effect. The use of a move-shoot turn seems to be the biggest change at this point. It removes a lot of player decisions such as having to decide between using TUs to increase accuracy/decrease hitbox by crouching, whether to scout an area by turning, whether to go back into cover after shooting, or whether to get in an additional shot. As Sowelu brought up earlier, this also likely means that both you and the aliens won't be able to do as much during a single turn. This might lower the skill ceiling, as in the original, while you could clear an area during a single well-planned turn and would be harshly punished during the alien's phase if you botched it, this one seems like it will reward your planning less as you have less actions and may be unable kill the aliens in a turn and punish your failure less as the surviving aliens have less time to wail on you during their turn.