a No way to tell the priority of a message. b No way to tell if a message has attachment. c No way to tell if a signed message has an attachment irrespective of whether it's been parsed or not. d A message replied to/forwarded cannot be marked unread by clicking on the status column. If you do it otherwise, it loses the replied or forwarded marker till marked read. e Clicking on the reply icon in status bar takes you to "Sent" box without warning, forward doesn't. f Clicking in flag or lock column of any unselected message toggles the markers. Doesn't happen for read/unread markers.
1.9.11cvs8 fixes b, c, and f. a) won't be done unless someone sends a patch with a new priority column (hidden by default) d) won't be done either, to avoid too much columns e) won't be done either, because there's no way to find a forwarded message back, and because it's useless to see a forwarded message imho. It's the same...