One more chirp: figured it out. Pretty easy, and I thought I'd pass it on. Luckily, you folks are using really easy-to-target classes.
We're using Edit Flow for custom post statuses. So in our workflow, we have five types:
Published (in the past now)
Scheduled (in the future now)
I'm using WPMU's Ultimate Branding plugin to target WP backend CSS, but I'm sure there's a freebie in the repository that can get the job done just as well.
The target classes are:
/* Published */ ul.postlist .post.publish
/* Submitted */ ul.postlist .post.submitted.draggable
/* Green-Lighted */ ul.postlist .post.green-lighted.draggable
/* Copyedit */ ul.postlist .post.copyedit.draggable
/* Scheduled */ ul.postlist .post.future.draggable
.post.publish is the native class; the rest, just plug in the names of your statuses (be they custom or WP native).
I hope this helps someone!