Thanks to Kotaku for tweeting their link!
Brian Ashcraft has posted an interesting read on Kotaku. With the emergence of the new 47 Ronin posters yesterday, Ashcraft takes a look at them from the view point of the Japanese people who are well versed on the traditional story. As he notes adding witches and giants and other magical components to the story would be akin to peppering a film on the Alamo with giants.
When all is done and said, comments by Japanese readers appear ready to accept the story for what it a magical take on a legend that may be fun.