This thread certainly wended far and wide. If it's not too late, I have a few comments on the new Control Panel itself and its associated features.
Where has the last time logged in time gone? Couldn't this be displayed immediately under the "Control Panel for ..." row?
I prefer the way that received and sent messages display on the same page curently. I don't understand what the advantage of separating them is, unless it's to accommodate people who have a lot of messages.
With so little help for users, W3T could benefit from a bit more judicious use of descriptive labels. What "Remind Me" and "Favorites" do is not obvious - and the screen with the explanation flew by so fast that I was only able to read the first line. Remind Me will be especially confusing for users. Remind me to ... what? Check this thread? That would be my first thought. While you might not be able to fit more text on the thread pages, I'd like to see the Control Panel label be more explicit, perhaps something like "Remind me to Reply".
I guess "Favorites" has become universal, but I think you'll find that more than a few users will think this option will add the thread to their browser favorites. Off the top of my head, though, I don't have an alternative other than "Watch" and "Watched Threads" from newsreader terminology.
The delete icon for Reminders does not communicate. The common X used for delete would be better. (I couldn't get any Favorites to show in the Control Panel, so I don't know if it's the same icon.)
On the new options added to threads, I think that "Post Options" is potentially confusing, because it reads as the options have to do with posting, rather than options for a post, and the meaning of the icons other than the one for print are not obvious. If you don't want to call it "Message Options", I think "Options" alone would be better. I'd also like to see them have text attached, as the Reply icon does, or have an option to display as text alone. Or, could a tool tip display for them at least?
sam~