It is possible to way (or perhaps a wordpress plugin) to create a given content key in WordPress (i.e. posts, pages, media, custom publish types) behave as a taxonomy? I essentially wish to setup a 1-to-many relationship of 1 item inside a given publish type to a lot of products of the different type.

So essentially, I've got a custom publish type, refer to it as Authors. I wish to make use of a Publish Type as opposed to a taxonomy because I need a ton more meta data than the usual taxonomy enables.

Then i have another custom publish type known as Books.

It is possible to method to put a box like the Groups or Tags metaboxes around the Author write page that display a listing of all of the books. I'm able to then select from a listing of all of the books, thus developing a relationship.

If the does not already exist, I suppose I'll write a wordpress plugin for this. I decided to give mtss is a try first, just just in case.

Have you thought about adding new meta fields to some custom taxonomy? Regrettably, you ned either to produce a new table for that meta storage or use wordpress_options, however it works and it is relatively future-friendly. Make sure to start your option names by having an underscore, though.