The only current prepro that could actually process 24+6.2 channels would be the Trinnov Altitude 32 http://www.bigpicturebigsound.com/Dolby-Atmos-Preamp-Processors-A-Buyer-s-Guide.shtml I don't have any experience with actual audio content that is encoded / mapped from a BluRay disk or any other source, though Dolby does supply info for folks to incorporate Atmos into existing surround based mixing workflows so I suppose you can deduce that the various x/y/z spacial info is in fact part of the digital stream and then it is up to the prepro to properly setup for accurate playback -- http://www.dolby.com/us/en/technologies/...ound-manual.pdf

Even assuming you had relatively high efficiency speakers in the ceiling, with nicely matched voicing and moderately narrow dispersion, it would be a challenge to get things sounding nice for all the listening positions. It is still going to be a struggle to get each seating area its own sweet spot. The conceptual way that Dolby markets Atmos for cinema, as an "object oriented" process that "frees sound designers from channels" translates to an ANALOG world still means a whole lot of amps, wire and measurements to get the levels and time delays working...