>The new interface looks absolutely terrific, however, I like to see the first few lines of the currently selected message in the lower pane. With the size of the header now, even if I split the two panes 50/50 I cannot see the message itself in the lower pane, only the message and thread information. Is there anyway to turn the header off?

The suggestion is great. If more would like to have it, we could have an option to show the header at the bottom of the message. Would that do?