An updated USBConfiguration.plist in the most recent version of iPhone OS 3.1 beta offers compelling evidence that Apple has continued development on an unknown device, referred to as "iProd," that was first discovered in March. A developer alerted us to the appearance of the new device description for iProd1,1 inside the configuration file. As most Apple devices are assigned the "1,1" designation in the first revision, this leads us to believe that there is indeed an unknown product inside of Apple under active development running the iPhone OS.

When the iPhone OS 3.0 SDK beta was first seeded to developers, an entry inside the USBConfiguration.plist indicated that a device identified only as iProd0,1 existed inside of Apple. The .plist item was nested among the usual iPhone and iPod Touch identifiers, as well as iPhone2,1, which turned out to be the iPhone 3GS that was released this past June. As shipping products from Apple don't have a leading zero in the identifier, we speculated then that it was a prototype device that was in active testing.

The iProd1,1 device has been assigned a new productID of 4762 (versus 4757 of iProd0,1) and assigned a different ConfigurationDescriptor of "standardMuxPTPEthernet." iPhone models also have this designation, and the additional interface identified in the plist for this configuration is "AppleUSBEthernet." The consensus here seems to be that the new device may have gained high-speed networking capabilities—though the iPhone uses the interface to tether to a laptop to share its 3G connection.

While it's easy to speculate that this may be the rumored Apple tablet we keep hearing so much about lately, we have yet to find any evidence that iPhone OS 3.1 is capable of running on a device with a tablet-sized screen. It's just as possible it may refer to the camera-equipped iPod nano, though we doubt such a device would run iPhone OS. Hell, it might even be an iPhone nano.

What we are willing to bet on is that with a 1,1 moniker the product will see public release soon—perhaps as early as September, when Apple typically unveils new iPods. Start saving folks... the time for the mystery iProd is nigh!