Good point. I've been getting rid of the old (like, before version 1.2) roundy gradienty touchy feely stuff as I find time to work on it...
How about the same refresh icon as used in the icon bars, would that be too repetitive? Or just right, since it's consistent.
Here is a rough test, just trying things out... It seems some sort of background is needed for the per-account unread counts, so they visually stand out from the folders. It does look cleaner and more modern, though.
Also attaching - a couple of message list screenshots (all the messages there are "read", and the contact icon is "weird", but that's just what I have for that particular one...)