So looks like this is 100% based on the new 52 comics.
Any one who got to read the awesome Shazam! New 52 run by Geoff Jones and Garry Franck can tell by the trailer that this is going to be an adaptation of this particular story so without a doubt we will get to see the entire Shazam family in that film. Only thing I am curious about is how they will change the story to exclude Black Adam who was the main antagonist of that story line. Also, I do hope they will keep the human manifestations of the seven deadly sins like in the comics. Looking forward to this a lot more now that I have seen the trailer.