The retail version of Harry Potter and the Deathly Hallows Part 2 goes on SALE tomorrow, November 11. This means you can purchase it at this time from retailers such as, Walmart, Target, Amazon, etc.
The rental version release date of the same title will be on December 9. This is when the library, Netflix, Blockbuster and Redbox will receive the DVD.
The library will have DVD available on the December 9, which is the date Warner Brothers makes it available to rental establishments such as, Netflix, Redbox, and libraries.
Please see the post about Warner Brothers for more information.