After watching the gameplay over and over a few times, I've come-up with a few points. These are not being sorted in positive or negative lists because, well, to each their own.

-I saw no reference or indicator to a degration or repair system for weapons or armor when the inventory system was shown

-The UI doesn't have the same style as the previous games and looks more simplified and...well...I'm going to be getting a UI mod ASAP

-I really hope power armor doesn't always bring with it that mech-mode thing.

-I'm interested how they plan on handling the skill/perk system

-The first BoS you see has torn-up armor. Either it recently got damaged (seems armor can break apart), or they aren't in the best of shape faction-wise

-The MASSIVE ship crashing to the earth has a BoS symbol hidden behind the flames beside (what I assume) is the ships name.

-Ability to build a community(s) is neat and I really just want to see more of it before I pass judgement.

-Custom weapons is fantastic, and it looks as though weapons have more stats to look at (range, rate of fire, accuracy, what looks like different damage types)

-Don't like animals spawning from underground. Seems like it would make it MUCH harder or Perma-death or more conservative players

Basically I like what I see, but really...we need more info. Hopefully in the coming weeks and months we learn enough to really see what's what. As of this moment, my only serious complaint is the UI. It looks kinda kidish, if that makes sense. Like they cleaned it up far too much. But that is a purely subjective opinion.

What mech mode thing?

This?: http://i271.photobucket.com/albums/jj125/Gizmojunk/armor_zpsl56chxim.gif

That's the best thing in the video. That's what power armor is, and how it should have been done in FO3. They finally did one thing right by the series; and by the looks of it, the only thing right IMO. I'm happy with it...But it doesn't make up for everything [the enemies] popping out of the ground.

what's the issue with enemies spawning from underground? I miss something...

Silliness; and convenience I think. It might be the kludge that pays for the enhanced graphics by effectively removing the need to draw distant enemies. Though it might just be that we saw a lot of ambushing; possibly these are their method for random encounters. The mole rats were okay... but it was pretty bad with the scorpions, and ultra-contrived with the Deathclaw.

Well shouldn't mole rats be tunnellers anyway?

I had a weird glitch in Fallout 3 of a mole rat running on its hind legs towards me, I almost forgot to shoot the thing, beause I was so surprised by this strange naked humanoid thing running towards me.

Power Armour wise......looks like they are heading back to what it originally was.

Yes.

The problem is that the enemies in the demo appear to swim through stacked dirt, like https://www.youtube.com/watch?v=wfPdveKKJqY through stacked gold.

A deathclaw came through the ground. Did not see that. Of well guess i have to go watch it again.

Tunnelling is fine for some creatures, I do hope it's not all of them (also, yeah, if they tunnel through concrete that would be wrong). I like the power armour, and I'm a bit concerned about the skills and repair system (you're trying to survive in a wasteland, a repair system is important, way more than in Skyrim, and I wish it was in that too tbh). Customisation is great.

yes, its power armor not an mech still you don't put it on as you put on normal combat armor.

Think you enter russian space suits from back too.