I thought Jim Emerson's post on The Happening was interesting and valuable: Emerson goes into detail about Shyamalan's filmmaking choices - his compositions and staging and editing - which is something critics rarely bother to do anymore. (I don't do it either, but I'm not a professional). I still think that he's talking about the movie as a failed attempt at doing something it's not trying to do. Jim's comments seem to be about how he would have filmed the same kind of material and what he needs from that kind of movie. Fair enough - but I think he gives short shrift to the way Shyamalan is consciously going against the grain of how scenes should be filmed (per the conventions of contemporary filmmaking) in order to work out his own visual ideas. For instance: the first classroom scene is constructed to set up the groups vs. individuals motif that runs throughout the movie.
Keith at The House Next Door seems to like The Happening more than anyone else but me and Roger Ebert, but his take is very mixed. Keith's points are interesting because he's definitely a Shyamalan partisan. Like me, he has a lot of admiration for The Lady in the Water. He sees The Happening as a movie partly done in by the compromises Shyamalan makes between his own personal way of making movies and his attempts to appeal to a popular audience. I agree that The Happening is a step back from The Lady in the Water and The Village to something that tries to be more "audience friendly" - like Unbreakable - but, for me, this is kind of relative. After the drubbing he took over The Lady in the Water, it's understandable that he'd do this, but he doesn't pull back too much. The Happening is still very much against the grain.
On the level of interpretation, I don't think the various theories the different characters come up with about the event in The Happening represent an attempt to spell things out to the audience. Rather, I think this plays into Shyamalan's concern with interpretation (a kind of storytelling) in general. I think Signs and The Lady in the Water develop this theme in a more interesting manner, but I don't think the way it is played out here is "preschool".