I'm not particularly impressed with the first person hands so far.
Then again, hand deformations are incredibly hard to do right without proper simulation tools; there's very little muscle, but bones and tendons contribute a lot to the final look, and the skin has to stretch and fold everywhere. And due to the high number of possible poses (because of the large number of joints) it's also hard to do any type of pose-based fixes.
Another thing missing from the screens is the alien's saliva. It's a very memorable feature from the first movie in particular, there was a lot of behind the scenes work to get it right (including the use of a lubricant, according to the documentaries). Surprise: such fluid things are also incredibly hard to do, faking them in real-time is a considerable challenge once again.
I still think that the art direction, lighting, and shading, are of a very very high quality, the new screenshots demonstrate it very well IMHO. Quite true to the original movie's style as well, can't really understand the complaints...