I wondered about that myself, I heard a rumor of a extended cut release in theatres in August. I was hoping an extended cut release for Blu-Ray, I heard the original uncut movie was over 3 hours. I despise double dipping, and hate see that happen with Avengers.
"In the Collider interview in which Whedon explained an earlier cut of The Avengers was over three hours long, he wasn't claiming the studio forced him to cut out a bunch of great footage. He was merely explaining a well-known filmmaking fact that nearly all movies are initially assembled at lengths greatly inflated from their final run-time, and that part of the artistic process involves cutting out the fat for greatest effect. He even denies, in that same interview, that there will be an Extended Version, saying he is happy with the theatrical cut and that there will instead be a series of Deleted Scenes on the DVD."