Just a quick thought: this sounds like a good use for the new object states feature. I read this article a while back and I believe it gives instruction on how to handle multi-stage approval:
Hello Greg! Thanks for the link - I actually found that article right after I posted my question here. I'm at the last part about inter-group communications, and my first thought was "my client is not going to like the part where the content groups have to email each other." Do you (or does anyone else) know if notifications for changing object states have been rolled out yet?
I should also say, I've used the "ezapprove2" extension for a little while now (http://projects.ez.no/ezapprove2_for_4_1) and while the description states that it can be used to create "multistep workflows," I don't see how that's possible.
I wondered if maybe a Multiplexer might be the answer here, but frankly I've never fully understood what the Multiplexer offers outside of fine-grained control over which workflow gets run based on class and section.