It is the first time I have heard of the new format. As a DM, I must say I find the concept very interesting. I naturally have not had the chance to try it out, but, it seems very straight forward to use. It gave me the net impression of increasing the ease of use.
As for the OP assertion that not everything is there to run the encounter, I don't know, as it based of an adventure I have neither seen nor read. That being said, I tend to agree with Mouse on this one, I feel it is a good concept for many types of encounters. We cannot dismiss it on the basis of a minority of situations.
On the other hand, I would like to see how it works in whole adventure. I like my games to have a good mix of encounters : role-play, puzzle, fights, traps, etc., and a good mix of environment : outside, city, dungeon, etc. It seems to me that the Delve format would be ill suited for some of these. We'll see how it pans out in the future.
By the way, I get the feeling that this is a great way to teach aspiring DMs the ropes. Everything they need close at hand. One of the problems my wife had every time she tried her hand at DMing was the sheer number of referencing she had to do. She loaths to improvise, everything has to planned for her to work an encounter. This format does a lot of the work for you. It would be perfect for her, I think.