WideMail 0.5 has been released. WideMail is an extension to Mail.app that creates a Microsoft Outlook-type message viewer in the message pane, and allows for the message viewer to be placed on the far right of the application window, which is a more efficient layout for widescreen displays. This latest release adds much more comprehensive options for placement of information in the WideMail column, and a built in preferences pane in Mail.app.
This release also fixes one of the two bugs I just took screenshots of:

Attachment and mail status icons are really big in the threaded view!

Colors message don’t get the message applied to the WideMail column, creating a disconcerting effect if you have a few ordinary columns around the WideMail column.
The first bug has been fixed, but I am eagerly looking forward to more work being done on this wonderful extension. :-)