Ideally SW would be a game you play through in one sitting, in one evening. But you could play it again and have a different experience altogether.
Not that I want to change your mind, because at the current stage of design I guess you are right now, I don't even think it would be possible to change the direction of the project without essentially throwing everything up. But I do think that's a shame - not for the duration itself, but for what it will probably represent in the skill curve within the game.
One of the most interesting parts of any RPG, besides creating your character, is watching that character develop gradually. Becoming more competent in whatever area you decided to invest your levels/experience. If the game is really that short, it can only mean one of two scenarios in my head: either your character gains experience extremely fast, which would be at least a bit jarring, or he doesn't change that much during the game, which means the game is more static and the weight is all on the character's creation rather than its development.
In both cases I feel that a bit of the 'essence' of an RPG is lost, but I still have high expectations for this project. Literally it's in the top 10 of the games I'm looking forward to seeing what the final result will be like after the release!