I am so glad I went through this whole thread of 14 pages. I have been up for 2 days trying everything I can think of to take a new document put into a dropbox folder and attach it to an email for multiple levels to click approve. I just figured I wasn't doing something right. Glad to hear its in development, but sad to hear it's not done.
It's rolling out this week, should be available everywhere by next Monday morning (our deployment train starts on Tuesdays). Working on a blog post for it.
We are now working on the functionality to attach files to Approval requests.