Not only that, but Marvel has announced the new Box Set will come with a new briefcase design as well as additional content. From the Marvel Facebook Page:
The limited edition Marvel Cinematic Universe: Phase One - Avengers Assembled Collection has been delayed and is scheduled to ship in Spring 2013. The Collection will come in a new briefcase and include even more than the content and features that we had first advertised.
The original Box Set was going to use the "indestructible" brief case that housed the Cosmic Cube, but Disney never got permission from the luggage company, who in turn filed a copyright lawsuit.
The lawsuit then saw Amazon pull The Phase One Box set in addition to the official Disney site.
Now, it looks like Marvel will be going with an all-new original design for the briefcase, or Disney has settled with the luggage company.
While you wait for The Avengers Phase One Box set, which contains all the Marvel Studios movies, The Avengers Blu-Ray will be released on September 25th.