I'm a bit worried because the previous videos was all about what you can loot and treasure chests, not about the actual story content.
IS there any mentionable story?

Yeah, the marketing videos haven't been that useful, just "hype".

From some of the Dev's replies on the Steam forums, I gathered that there is a main story. There is something like a central hub level where you prepare and can pick up side-missions. These side missions takes place on the same maps, so (I am guessing here) you may revisit previous maps to do them or do them at the same time. The main story progresses as you take the "main quest" missions.

I don't think there is any branching - it appears to be linear, and it is a toss of a coin how well the story will be told. The 40k atmosphere looks good though. I am a bit worried about the looter-shooter aspect myself - I'll rather not have to wade through lots of useless loot in this sort of game.

Thank you for the anwer.

I don't mind linear games at all, what I DO mind are games which basically consist of loot chests and/or challenges.

I'm still not convinced. "Side missions" sounds good, as long as it's not just "kill boss, get stuff".
Apart from the gameplay itself (locomotion, AI, level design) for me in such a game it's most important that there's actualy characters and not just NPCs and some kind of story (doesn't have to be Nobel worthy). The franchise would be wasted if it was just used for optics.
Of course I can also do without any story at all (just finished Turrican 2 again), but after having read many stories from the Warhammer universe I DO expect a bit more than just action and loot.
These trailers really are among the worst I have ever seen. No one who hasn't lost his accountability focuses on describing the loot and how to sell it ... the best trailer was "Enter the Hive" which gives a little hope for some actualy content.

Well, I still got a day to gather some information before I decide if the preorder stuff is worthe the risk of wasting the money.

From the videos of the first level that are floating over the youtube the chests more look like a weapon and ammo point. The shooting part didn't look too impressive, however it is possible that it is just b/c it is first level. Dunno, need to see a proper review... I wish demos were the thing like it was at least 10 years ago...

There is loot but it's not showered on you like Borderlands, and so far, the loot pickups have been worthy. You're not chucking guns over your shoulder every 30 seconds.

What I can say is the gunplay if fantastic once you get into the groove. A very frenetic ride.