I don't know if there's a plugin that does this yet, but
this guy did something similar when he modified Wordpress to run a magazine site. The article is a bit long, but he has the theme with the base coding
available here. I played around with it for a little bit a few months back, but never really had a need for it personally. Not sure if this is exactly what you are looking for, but it might give you a base to adapt it to your specific needs.
