Screenshot of some new Gmail features. Others have ATOM feed buttons but I haven't been able to verify this.
Note the conversation pane below the contact view and how you now have much more freedom to customize the information for each entry.
Not as significant are the elipses that neatly cut off the label names and the movement of the invitations link. For more info about other features such as saving drafts, automatically forwarding email, go to Gmailforums.com
UPDATE 10/5/04 5:37 PM EST: Here's the link to the ATOM XML feed.