It would be great to have a Sonos 'Pro'. This could be a multiple zone system, with multiple digital and analog outputs to drive multiple amps in a whole house system. Basically, you could buy one Sonos 'Pro' box, say a 6 zone model, that would have 6 digital and analog outputs. These 6 outputs could then hook up to a 12 channel amp, or multiple amps, which would in turn drive the inwall speakers.
This could be a product that would have a cheaper 'per zone' cost, but would cost more than a single zone Sonos currently costs. Say, for example, $2000 for a 6 zone model, instead of 6 x $499 for 6 individual sonos boxes. There is a niche for this product, for all of those who have whole house systems. Sonance, Niles, etc. don't have anything that comes close to Sonos, but they have systems that are better integrated into the whole house. They don't seem to realize that CD's are so last century.
Sonos is great because it puts a simple interface to a back-end music server. So many music systems for whole house audio are designed for CD changers; as opposed to being designed around TCP/IP and server based connections.
What I am starting to get is a big pile of individual Sonos amps stacking up in my basement, with individual feeds going to each. A multi zone system could clean this up, perhaps save me a couple of bucks, and offer me the opportunity to utilize the excellent remote control of Sonos and combine that with a different amplifier system. It could open Sonos up to a much higher end marketplace.