Just got an email from amazon about the box set being delayed.
We're writing to let you know that the Marvel Cinematic Universe: Phase One-Avengers Assembled Collection will not be released by Marvel as originally expected. Instead, Marvel is planning to offer a similar collection in new packaging. The new collection will include the original titles offered with the first version of the item, and is expected to be available in the spring of 2013. To make this easy for you, we updated your order for the original collection and will ship the new collection when it becomes available. The price of the new collection will be the same as the original collection.
To show our appreciation for your understanding, we are providing you with a promo code to receive a free copy of Marvel's The Avengers (Two-Disc Blu-ray/DVD Combo in Blu-ray Packaging). To be eligible, you must have placed your order between June 1, 2012 and August 28, 2012. Any cancelled orders are not eligible to receive the free copy. Codes must be redeemed by October 15, 2012.
Pretty cool. Now I can watch the movie when it's released, and get the box set without having to pay twice.