Well, regardless of the system choice, I'd still recommend running wiring matching the CEA standard (exactly what the Essentia would require anyway).
Not a lot has changed in the world of wall panels, but I hope that we'll see new products at CEDIA in that space... I agree that the wall-mounted panels provide significant value, even if control is (also) available via handheld/wireless iDevices.
For a two-zone system, you might thing about just two Sonos units (one per zone), centrally located, and placing a somewhat dedicated iDevice for control. Hopefully the enhancements to iOS6 will make it easier to dedicate an inexpensive iPod to this function (the single-app lock mode, etc.). NuVo also has a Sonos competitor announced (still not shipping, though) - the P3100 3-zone unit would be a good choice if it lives up to its description. But no keypads on that model, either.
You say you'll use an iPod as a source - you could also rig up an auto-sensing amp (like the excellent-value AudioSource AMP-100) and an Apple Airport Express (cheapest AirPlay device) for each zone, too. The issue with using an AVR or other Airplay devices in this manner is the need to switch "apps" between the AVR control and the source/song selection...