http://www.amazon.com/gp/product/B000X9 ... B000X9FLKM
It doesn't give a date when it's actually going to be released.
Just the theatrical versions, though, which has a lot of the reviewers up in arms. You can also go
- here - to sign up to have Amazon notify you when the extended edition Blu-ray is available. (Although rumors are that won't until the two Hobbits' are released in 2011-2012. You can also hold out and see whether you can buy all FIVE in one boxed set.)