It sounds like a great idea! How about just giving it a try? You could treat it as an experiment. After all, you will benefit from the experience of breaking away from traditional format, and may discover something totally new in the process.
I think `raspil and ~KyteGlory have the best point here. I think it's a good "let's learn something/practice/have fun!" idea - so certainly worth doing. But if your sole purpose is to produce something for readers, I think you're doing it for the wrong reason.
I like the idea a lot. Personally, I can't see how something can be "fun for writers and boring for readers" as the emotion put into writing something reflects on the readers, but that's probably just because I have no idea what I'm talking about. Potentially (not factoring your linguistic and story-building skills), you could spawn a more digestible version of that godawful "39 Clues" series that had many authors working together. tl;dr just go with it. It sounds alright and you never know.
I wanted to first meet in a group and set the scene and cast of main characters. I would then do the transition stage with writers of different styles to try and bring the book to a well rounded style. In end I would then like to meet again and decipher the ending as a group and edit the story as a whole. I am not sure it would work but I always try to think of what has not been done or is in all fact different from the normal trends of what is popular or normal.
It's essentially roleplaying at a massive word count. Like all roleplaying, it's great for the writers and horrible for the readers. You might have fun. You could potentially learn a ton. But the story you produce is bound to have a broken plot, schizophrenic storytelling, and an overall lack of cohesion. So it's good for practice, but bad for your resume. Mind, it's perfectly fine if you want to do it just for fun and experience. Just don't expect that you'll turn out a masterpiece.
One thing I have seen done that tends to work out is when authors each contribute a short story to a single theme or overall narrative. Since each author's contribution is self-contained, it avoids most of the problems that arise when authors who don't share a mind try to share a story, but there's still the sense of building off one-another and creating a greater whole.