Caught it last night and left the cinema having seen an enjoyable film. I think justindeimen has hit on several valid points in his comments for the film. I'm glad M. Night Shyamalan hasn't made the same mistakes as directors like Peter Jackson, always thinking that their next project has to be bigger to be better or repeating their previous successes (which would have been the easy option for him). 

Lady in the Water is a child friendly fantasy and an optimistic tale for anyone of any age.

Cheers Trev.