I own an iPhone, iPad, iMac, Airport Express, Apple TV, several Sonos zone players and a Sonos CR200 touchscreen remote. I'm an iOS developer as well and have been running the iOS 4.2 beta with airplay since the day it dropped. I also own a home automation / AV distribution company and i've played with more music distribution systems than i care to count, from the cheapest iHome radio to the most expensive Crestron system. i'm also a musician, and i take my music listening very seriously.
If you're looking to set up quality multi-zone audio, sonos is the ONLY way to go, and actually works out to be more flexible and CHEAPER than apple. Plus Sonos has already said they are looking into airplay and will more than likely add this via a simple software update, just like denon did. (sonos is known for frequent, and useful updates)
COST
airplay requires an individual iphone/ipod/ipad ($230-$830) or a mac running itunes ($730-$1500+) for each unique audio stream. plus you need an airport express or apple tv ($99) for each audio zone. so you're starting at $330 with only 16gb ipod touch and airport express, or starting at $800 for 320gb mac mini and airport express... and you STILL need an amplifier and speakers...
the sonos zone players average $450 for a truly respectable sounding amp/speaker combo, or just the amplifier model that you power your existing speakers. and every sonos zone you add gives you a unique audio stream so each room can listen to different music or be easily grouped in any combination with the other rooms.
FEATURES
- every sonos zone player also has a line in for a cd, ipod, or other analog source which streams out to any/all other zones. apple has pretty much 0 support for analog/local sources.
- itunes internet radio is terrible... sonos has consolidated nearly every am/fm station, internet radio station, pandora, last.fm, and iheartradio. compatibility with subscription services rhapsody, napster, spotify, sirius, and wolfgangs vault. all through one consistent simple GUI.
- the subscription service's on demand tracks can be side by side in your playlists with tracks from your local mp3/aac library.
SETUP
Sonos has about the easiest set up process I've ever come across. You plug it in, power/ethernet/audio. The zone players all have a two port network switch in the back, so no need for an extra network switch. You can run the entire setup from the iPhone app (which I do routinely at my customer's homes). Enter language, zip code for am/fm, press the single button on the zone player and you are done. Apple TV is pretty easy too, but first you need homesharing set up, navigate settings on the Apple TV and in iTunes, enter the pins, etc. Not that big of a deal for you, but the average consumer is already intimidated i assure you. Airport Express requires airport utility for mac, and is definitely not as easy as it should/could be.
AIRPLAY? BATTERY DRAIN MUCH?
by the time i get home at the end of the day i need to leave my iphone by the charger, i don't need to drain the battery further by streaming audio. my sonos system is controllable via app on my imac, iphone, or my ipad if i'm reading on the couch. but honestly, if my iphone or ipad isn't already physically in my hand i reach for the sonos touch screen remote. it's got a motion sensor so it's instant on, no swipe to unlock, launch an app, etc.
CLOSING ARGUMENT
My closing argument is that having used both, the sonos app for ipad and iphone is better than apple's remote app. It consolidates far more music services than apple is interested in offering you. And I am quite certain Sonos will be adding airplay compatibility sooner or later.
And finally, maybe you haven't noticed, but it seems to me apple has been spread a little thin lately trying to roll out iOS updates for iPad and iPhone, reinventing laptops, etc. and their priorities are ever changing:
http://gizmodo.com/5603424/why-has-apple-neglected-the-remote-app-because-just-one-guy-made-it
Sonos on the other hand lives and breathes multi-room audio. As a daily user and critic of both Apple and Sonos products, an iOS developer, home automation specialist, and a musician, I assure that you Apple has not bested Sonos... not yet.