Configuration files in each version of iOS used to contain entries that referred to future and current iOS devices. For example, a reference to 'iPhone 4,1' became the iPhone 4S, etc.
With today's release of iOS 5.1 Beta 2, Apple has added numerous fake references to devices that don't exist and likely never will.
One file in particular, USBDeviceConfiguration.plist, had formerly listed about two dozen different device variants. As discovered by Mark Gurman, that list has now ballooned to well over 100 such entries as Apple has seeded it with dozens of new fake references to such future products as "iPad10,1", "iPhone11,3", "iPod11,1", and "AppleTV8,3".
This is clearly an attempt by Apple to make it more difficult to figure out which reference is a real product.