We just met up with the folks from Sonos, who are in New York showing an alpha version of the company's upcoming free app that turns the iPad into a giant Wi-Fi remote.
As you might expect, the iPad app looks a lot a like Sonos' iPhone app but the iPad's larger screen shows off more info at once, so you don't have to toggle through a couple of windows to set what music's playing on each ZonePlayer. You can even drag and drop songs or services (such as Pandora) onto a Zone to play those tunes in that room. In all, it's looking good, and the Sonos reps said it should be available for download in late August.
Discuss: Sonos prepping iPad app