It seems that iOS 4 is ready for devices that haven't even made it to the streets. A source at Apple told the folks at BGR that there is a some code in iOS4 that queries the device it is running on. If the device is either a CDMA iPhone or iPad 2, the device auto-activates and bypasses the need to run iTunes.
The source also stated that this code is a regular inclusion every year before a device release to allow field testing of devices without activation and usually removed before launch. This does add to the rumors of the CDMA iPhone being on the verge of arrival, and the iPad 2 inclusion is interesting as well as it may be hitting field testing soon.