Several Japanese language websites
reference a CES demo of Audyssey DSX (Dynamic Surround Expansion), another surround/vertical height enhancement technology, which provides upmix to 11.1 channels. [UNAUTHENTICATED image...
Audyssey DSX places the LeftHeight/RightHeight speakers at 45 degrees from centerline; this is outside the 30 degree position ["above LeftMain/RightMain"] of corresponding
speakers in the Dolby Pro Logic IIz (9.1 channels) and DTS Advanced NEO (rumored up to 12.2 channels) speaker configurations. However, it may be close to the position Yamaha currently uses for FrontPresence speakers, and might also be an acceptable placement under Dolby Pro Logic IIz.
Audyssey DSX places the LeftWide/RightWide speakers at 55-60 degrees from centerline. The DTS "7.1 Front Wide" [alternative] speaker layout places the LeftWide/RightWide speakers at 60 degrees from centerline [however, I'm uncertain whether LeftWide/RightWide speakers are used in the DTS Advanced NEO configuration...]
As Dolby Pro Logic IIz appears to include (and replace?) Dolby Pro Logic IIx, [and is already announced by Onkyo
,] I expect we'll see DPLIIz "everywhere". The DTS and Audyssey technologies might have more acceptance issues...?!AFTER THOUGHT: For each of my three surround systems (of varying age), either the LeftWide or RightWide speaker position (or both!) is unworkable for both floorstanding or bookshelf speakers were I to consider such an addition...