...you ought to read the original book! Not really scary- but very different from the Disney version we all know and love. I grew up loving the movie as a kid, but when I had to read this for my children's lit class, I was shocked! Mary Poppins is a real jerk in the book- not just quirky and eccentric like she is in the movie. My professor even tracked down the the chapter which P.L. Travers removed from all subsequent versions of the book about twenty or thirty years ago. I'm sure it was a product of the times, but even so, it was pretty offensive.
Now on the other hand, if you ever get a chance, read J.M. Barrie's Peter and Wendy (sometimes called Peter Pan) or the prequel Peter Pan in Kensington Gardens. As much as I enjoyed the Disney version, I don't think it even comes close to capturing the kind of magical world Barrie created almost a century ago. Very sweet books.
It amazes me how widely varied different interpretations of the texts are.
BTW, I loved this trailer!