updated 12:18 pm EDT, Mon October 8, 2012
Could be meant as effiency upgrade, China Mobile edition, or something else
A recent version of the iOS 6 firmware may hint at a new iPhone 4 model, reports say. The firmware is listed for an "iPhone3,2" and actually started appearing as a download option on September 19th, but still hasn't been pushed to developers. The GSM version of the iPhone 4 is the iPhone3,1, while the CDMA model is the iPhone3,3.
What a new iPhone 4 might have is uncertain, although there are several possibilities. It could, for instance, follow in the path of the iPad 2, which got a late-life circuitry upgrade that improved its power efficiency. It could also be a "world phone" device, capable of operating on both GSM and CDMA networks. Still another possibility is a 4 built for a previously unsupported carrier, such as T-Mobile USA or China Mobile.
The 4 is now Apple's bottom-rung iPhone model, often free from carriers on contract. Introducing a new revision could be unusual in this light, but might be meant to sustain sales, or alternately just reflect advances in chip technology.