updated 09:15 pm EDT, Tue September 6, 2011
Carriers may now have special iOS 5 builds
An as yet unverified rumor Tuesday has the "most prominent" iPhone carriers getting special late-beta releases of iOS 5 for testing. These supposedly differ from beta 7 in having 3G-capable FaceTime, which 9to5 understands is a "high priority" for testing. As with tethering and other carrier-dependent features, though, it might not be enabled when iOS 5 arrives.
Also supposedly enabled is the Nuance-based voice command system. Similar to what's present in Android from 2.2 on, users may only have to tap a microphone key to dictate text or otherwise speak out commands.
The Siri-based iOS Assistant task completion app, however, isn't said in this cut of the OS. It could be reserved for the iPhone 5 or may simply not be far enough into development to be ready for field testing.
Key carriers have always had at least some kind of access to an iOS release to make sure it doesn't create problems on the network or trigger widespread complaints from early upgraders. Their access to unannounced features is less certain. However, they often need to have an experience as close to the shipping release as possible, and with an iPhone due in or before mid-October, any iOS builds would have to show all or nearly all of the full launch day feature set.