Science Fiction Time ?

How about this: a purely digital vaccuum array. Instead of speakers pushing the air, one has dozens of tiny vaccuum modules around the room. They receive a digital signal, and create a vaccuum of a certain strength, for a certain period of time, depending on the signal. The system would be infinitely adjustable depending on characteristics of the room, such as air pressure and temperature, and could also 'detect' objects in the room, such as listeners, and adjust. I'm sure at some point some physicists will solve the problem of aiming a vaccuum.

Another idea, to deal with room reflections and the like, would be to have a tiny speaker (rougly cylindrical or rectangular prism-like), and have it rotate in 3 dimensions REALLY fast. This way it could send a sound signal in any direction, and also send radar or some such in essentially every direction in order to give itself feedback about variable room shape.

Can't wait to hear other (more reasonable) ideas.

My favorite is the transducer (i.e. speaker) the size of a quarter that emits hyper frequencies (around 250 khz) that, when mixed with other hyper-freqs, magically reduce to human range (20-20K) and can be "focused" into a local "hearing zone" so you all can watch home theater, at full volume, on you couch while the baby sleeps in the next room. This is actual technology owned by a company in (last I heard) Poway CA.

Digital room conditioning, as you put it, is already here. SigTech, Snell, Meridian, TacT, etc.

I envision a recreation of a live musical performance, displayed as a 3-d , moving, holographic image, right in your living room, from some type of hologram projector reading a massive block of computer memory as the storage device.
The complete performance with the musicians performing in the original environment they recorded in, is projected in a 3 dimensional reality in your living room ,as you sit in your favorite listening chair.
Audio quality is 98% of actually being there. Speakers are eliminated as a device has been invented which modulates the surrounding air in your room to recreate an almost exact analogy of the pressure waves generated in the original recording venue.

Listening rooms injected with floating gaseous particles each containing a microscopic loudspeaker, the signal from the amp beamed to each particle, the position of each particle kept in position by an electro-magnetic force field.