Google AdWords is beta testing a new AdWords interface. The beta test includes a small group of U.S. advertisers. If your account is included in the test, you should see a notification upon signing up to the account.
You can also request to be included in the beta test by signing up here.
Note that this beta test is for the interface and doesn't change how AdWords campaigns work (i.e. bidding, Quality Score, etc.). They're looking to improve the way users navigate their campaigns and edit campaigns across multiple ad groups.
Have you been included in the beta test? Let us know your first impressions by leaving a comment.