Just a quick update on where we are currently and what we a pursuing:

As you can imagine, there are a seemingly endless number of possibilities for system configurations, sizes, features, and levels of performance possible with any system that looks to free up wires. What comes with that freedom is the difficulty in narrowing down the options into something both feasible and desirable to the purchasing public.
Our first step toward developing any AirPlay capable product is to secure a workable hardware package and the required licensing that goes along with that search. We are speaking to a number of approved development partners and hope to begin work on the hardware side soon.
On the product side, I admit to initially having missed the fact the Apple has decided not to "allow" multiple device streams to be sent from their portable iDevices. This is really a shame and limits the desirability of our initially conceived L/R/Mono solution, in my opinion. During testing in the lab I have also discovered some minor latency issues between multiple AirPlay sources and a "catch-up" period for the two channels to sync after a network dropout. All of these discoveries have me leaning toward the powered airplay speaker + M3 slave idea, which will also be a significantly less expensive option. We are also looking at the complete "portable" stereo-in-one model which could be available with or without battery power supply.
The time consuming portion of the development of these products is going to be out of our hands, to a certain extent, as we have to involve development and licensing parties, but rest assured we'll keep you posted as we proceed.

Thank you for your input!