There are some pretty good elements to these pictures, in my opinion.
I quite like the Power Armour, and of course it is going to appear very different; animating a 3D model necessitates that is has to work, as it were, whereas a hand animated 2D character can be created with much more emphasis on aesthetics.
I think the Supermutant on the right looks better than any of the others seen so far, and it actually isn't so far away from a competent 3D rendering of a bald Fallout original. Once again, the switch to 3D necessarily makes the thing different. If you've ever looked at, for instance, a Simpsons or Family Guy action figure, then you'll know that they look very different - often weird - in 3D, because of the greater range of viewing angles. Now, I'm not claiming that there is any real attempt at fidelity in these redesigns, but I think that the perspective switch, coupled to a 3D engine, is likely to change the feel of any character.
None of this changes the fact that the game is more likely to be screwed by elements of story design, scripting, and changes in game mechanics, than by new and different art direction. These newer previews seem to be pushing the exploding nuke-u-lar car as a ubiquitous feature (I don't know what new material - if any - these guys have seen). Now that is just plain wrong; I might have forgiven one or two pulpy sci-fi mini-nukes, but if I have to spend my entire time explodicating old bangers, 'cus it are cool, then I'm not really interested.
Honestly, I find it quite frustrating that, even at this late stage, there are still some fairly obvious ways that Bethesda could maximize the positive aspects of what I've seen, but seem - if the interviews and previews are accurate - to be pushing everything that will ensure this game is a shallow, missed opportunity.