In Gmail, how can recipients be moved back and forth between the To and CC fields?

Question

In the Gmail web interface, when composing a message, is there an easy way to move recipients that are already entered in the To and CC fields back and forth between those fields?

I'm looking for a better way to do this than manually cut-and-pasting the text representing the recipients back and forth between those fields, making sure all comma separators are correctly in place.

Example scenario where this would be useful:

1. User Alice sends out a message to Bob, Chris, Dave, and me asking for opinions on a topic.
2. Bob does a "reply all" with his opinion.
3. Now I start composing a "reply all" to Bob's message to continue the thread with my opinion. At this point, Bob is in the To field, and Alice and the other recipients are in the CC field. My message is primarily for Alice (since she sent out the original message with the request for comments), so I want to move Bob to the CC field, Alice to the To field, and leave the other recipients where they are, before I send my message.

Answer 1

An ability to drag-and-drop recipients between the To and CC fields was just implemented in the new Gmail "compose" feature, being rolled out to everyone currently!

http://gmailblog.blogspot.com/2012/10/introducing-new-compose-in-gmail.html

Answer 2

I'm sure there is no functionality to do this in Gmail for now.

I couldn't find a Chrome extension nor a FireFox addon for this purpose.

But I think writing a UserScript for this would not be too difficult; so, if you have some JavaScript experience, you can give it a try and post it here.