In March it was noted (by many) that the iPhone OS 3.0 beta SDK contained a reference in a file, /System/Library/AppleUSBDevice/USBDeviceConfiguration.plist to "iProd0,1," sort of a mystery device. The latest beta update for iPhone OS 3.1 similarly includes a reference to iProd. However, the USBConfiguration.plist file now has the string "iProd1,1." Typically "1,1" is used by Apple when it releases first-generation products, like "iPhone1,1" for the original iPhone.
The new string was revealed to Ars Technica by a developer, leading once again to the requisite question: "what the heck is it?" Theories have been:
An iPhone nano. Probably the least likely rumor, as Apple just released their "iPhone refresh" for the year.
The rumored iTablet, a tablet PC that is reportedly a 10" multimedia and gaming powerhouse, that could possibly redefine the tablet PC category. One wouldn't expect such a tablet to use the iPhone OS, however.
New iPods (OK, more prosaic, but still rumored). There have been rumors of new iPods including cameras, and even cases showing up which would seem to fit such a form factor. September is when iPod refreshes typically happen, and such a more powerful iPod might require the iPhone OS.
We could just wait patiently and not speculate. Nah, where's the fun in that?