Recently it was observed on Vodafone UK’s site that the iPhone 5 will be available in 2 colours, black and white and traditional the 16 and 32 GB versions. This confirmation was seen on the Vodafone’s Sure Signal product page, which is a device that boosts signals where 3G signals are not available. So this confirms that the iPhone will not be available in a new 64 GB capacity as the rumours are doing the round.
There is a possibility that the listing is a typo, or even presumption. Earlier there was a leaked article in which it stated that the device is expected in early October and pre-booking may start as early as September end itself. But nothing can assure until an official invite for the event is out from Apple.