Google is changing the way Gmail looks. When users access their Gmail accounts, they will see a new interface. Users may still postpone the "new look" for now, but Google has announced that the new look will be permanent within a few weeks.
If you are a Google Apps administrator, you can use the, "One-time switch in the control panel" to have the interface change for all the users in your domain. That way you can determine when you will offer the new look throughout the domain so that all users have the same experience.
Learn more by viewing the attached PDF file at the end of this post.
Google Apps For Education K-12 Regional Leader