Check out Dolby PLIIz. http://www.dolby.com/consumer/technology/prologic-IIz.html

The Blu-Ray spec allows for 11.2 sound. That's 3 mains, 3 height, 4 surrounds, a "Voice of God" speaker - directly above your head, and 2 subs. Not quite sure how Audyssey plans to get around these specs...