The Happening is one of only two movies I've seen so far this year about which I feel evangelical (the other one was Boarding Gate).
I went into the theater knowing almost nothing about the movie: I had avoided watching the trailers and hadn't read anything about it. I didn't want to get caught up in the continuing anti-Shyamlan backlash (which seems to have been gorwing ever since Unbreakable). I had wanted to recommend the other people see the movie in the same way - going in clean, if you will - but I also wanted to make sure they were on the right wavelength, so I started bringing up Val Lewton and Jacques Tourneur in all my conversations about Shyamalan and the movie. I'm not sure that is "strong" enough, though, so my new suggestion is that people who are watching it make the leap of faith that it is, on its own terms, a complete success. In other words: everything in it is the way it is because that's how it's supposed to be, not because Shyamalan was trying to do something else but failed.
For instance, I don't think Shyamalan was trying to write "realistic" dialogue and somehow screwed up. I don't think he was trying to direct his actors to give gritty, naturalistic performances à la 28 Weeks Later, but couldn't get that across. I don't think he was trying for a thrill-a-minute feel and stumbled into making a movie that was more creepy/dreamy than thrilling/intense.
This isn't to say that because I think it is a success on its own terms, everyone has to like it. Taste and all that is certainly still important: you might not like the way he uses stylized dialogue, you might not respond to the performances, you might think that the creepiness isn't realized as effectively as it could be.