Get the most recent taxonomy/category?

Hi,

I’m coding a theme for a magazine (not a magazine styled blog ;), that has three sections. I’m using default categories for this.

To keep the editions organized, I created a custom taxonomy (“editions”), so the magazine admin will create a new edition, and assign it to each post as she publishes monthly.

My home page template is designed so it only grabs the posts from the latest edition, and then display them organized through custom queries. I’m OK with custom queries, but I have no clue how to get the ID of the most recently created edition.

Any ideas or pointers? Thanks!