Enough has already been said at this site and at many other places about the disappointment that Signs has churned out. So instead of giving a detailed review of the movie per se I thought Id mention some other observations.
Let me start with my very brief comments about the quality of the movie:
Did you like the movie - Yes !
Were you glued till the end - Definitely !
Acting/Music Score etc. - Lovely !
Did the ending disappoint - smile :) umm... read on ...
MNS, notwithstanding the small list of movies he has produced till now, has a central theme to the movie which he wants to convey. I believe he comes up with, what I would call, a central moral of the story. That is of primary for him. Please note that whatever be the moral of the story, it has got nothing to do with the actual story and characters.
Now when MNS really likes a moral of the story he then cooks up a story which does the secondary job of conveying moral of the story
So far so good - nothing wrong with it as long as the end product rocks ! Incidently his second movie Unbreakable was an amazing experience for me. I happen to be in that small minority which believes that Unbreakable was better than The Sixth Sense - anyway let me not digress.
The central moral of the story for Signs is clearly Nothing is a coincidence and all events (however trivial or sad or what ever they might seem when they happen) have their importance in the Grand Scheme of things. The movie definitely does an astounding job of conveying this to perfection. If you havent watched it then go ahead and see it to understand what I mean !
So what went wrong ? Why all this murmur around the world about what a disappointing ending and all ... I must confess that I too was disappointed by the movie.
Difference being I was not disappointed in the end. Half way through the movie I kinda figured that the ending would be rather bland - what eventually put me off and am sure is the central reason for most people not liking the movie is the fact that maybe ... maybe the story selection was not right.
A concept as strong as Nothing is a coincidence needs a story line which does not distract the viewer from it and leads to that concept. Though Signs does convey it but the concept of Aliens and all is such a strong concept in itself that the mind is diluted. As I see it when you in the business of making thriller movies (MNS) you must make sure that the viewing public is not distracted from the central theme.
So in isolation Signs is a very good Alien based scary movie and also has a very interesting theme to it. Possibly the two are so strong in them selves that mixing the two did injustice to them both and also the movie goer !
That was my two cents :)
Btw the Psycho fans will love the opening of the movie with characteristic reference to the Psycho theme music :)
IMDB mentions that James Newton Howard was specificly asked to compose the score with references to Psycho - Close Encounters of the third kind etc.