In reply to Zebulan.

Yep, I really want to see something along those lines in the long term. I'm patient enough right now that I want us to get all the other stuff right first. It'll definitely be a tough problem to solve in the editor. Of course, as you probably already know, there are applications outside of post formats for this too. Even just different templates based on the author, category, and all sorts of data can be useful in some site designs.