Those screenshots definitely do not fill me with confidence in this product.
Most of it is much more Fallout 4 and as for the new material, I really dislike some of the ridiculous stats for the melee weapons or that there are yet more weapons with special abilities.
The new armors are just plain ugly and who would wear a lobster trap as a helmet?
The rad chicken is just plain stupid, it is the 'everything is apocalyptic if you put rad in front of a name' trope.
Just call it a plain chicken, even if it has undergone some mutation from its baseline genetics I still it is close enough to be considered a regular chicken unless it has turned into some top predator or something that now attacks humans or has taken on other type of non chicken traits.
The new large crab mutant is a neat design but as another poster showed here, it is a rip off of someone else's game. Not that this is anything new as I have heard that Bethesda has 'copied' concept art before in the past for their own game.
The new lobster or prawn thing in the trailer was neat looking but gameplay wise it is just another version of the giant mirelurk to kill.
The angler fish thing is interesting but it is probably a Mirelurk king variant.
Note, variants do not have to be a problem as Obsidian also recycled several Fallout 3 creatures to create spore carriers and lurkers.
Actually learning more about Nick is not so bad as he was one of the better companions in the game but it is clear that the player must have met him or at least been to his office in order to start this quest/DLC, unlike Fallout New Vegas one (Okay, if you had met Veronica and recruited her, it would play an extra role when you met Christine and Elijah).
To be honest, I am not so sure if I want to know more about the Synthetics because despite their interesting sounding concept they were not that interesting at all, not a real additional 'species' to the Fallout universe as they could have been, existing next to Super Mutants, Ghouls, and so on.
Like others pointed out, this looks a lot like Point Lookout V 2.0. Now that was an okay DLC but hardly a stellar one and I would not buy Fallout 3 just to play it just like I will not play Fallout 4 to play this.
So far all of Bethesda's DLCs are big misses and no match to other SP DLCs for some other games.
Personally I am a bit sick of Bethesda's half assed attempt at shoving Lovecraft references or atmosphere into Fallout.
Nick has a brother he didn't know about.... Great, is he the evil twin, like Data and Lore from ST:NG?
I had not even thought of that one. Bethesda is bringing back the 'Evil Twin'.