I went to LSC tonight and saw this film for the second time. It's worth seeing twice because there's plenty left to learn about it after seeing it once. Some films are close relatives of the theatre and some are a completely different creature. This movie manages to be at both ends of that spectrum at the same time.
In terms of being very different from theatre, the movie uses a ton of different shots. Coppola cuts from one 30 second shot to another with reckless abandon. Fortunately this doesn't end up looking choppy or disjointed: the story is told in small pieces which fit together very well. Another cinema-only thing about this movie is the number of really wide (and really wonderful) shots of Tokyo; she has a lot of slow sweeps of the city as well as bouncy closeups of the two main characters running through the streets.
So why do I think that this movie could be successfully done on stage? Well part of it is the fact that there are only two critical characters. There are important small characters, of course, like the photographer and video director which provide the two best comedic scenes in the film. The story, however, is really told by just the two main characters. Furthermore, a ton of locations are reused (most notably the hotel bar) which means that one could rewrite it to use only a handful of the places in the film.
What really makes the film so good is the way Coppola manages to use the cinematography and sound to accentuate Murray and Johannson's performances. The two actors tell the story while the director tells the story using the opportunities afforded by her medium and the combination presents a contemplative and compelling piece.