Engadget has found references to two new iPhone models and three new iPad models in the iOS 4.3 firmware.
If you dig far enough into iOS's code, you'll eventually come across iPhone3,1, which is the AT&T iPhone 4, and the analogous iPhone3,2 (i.e. Verizon iPhone). It's nothing we haven't seen before, but then along comes iOS 4.3 with a handful of new mystery identifiers to spurn speculation -- namely, two new-generation iPhones (4,1 and 4,2) and three iPads (2,1; 2,2; and 2,3).
Its likely that the new iPhone models represent the GSM and CDMA version of the device and the three new iPad models are WiFi, GSM, and CDMA variants.
IPhone3,3 is for CDMA with micro R-UIM card tray, similar with microSIM card for iPhone3,1; iPhone3,2 is for CDMA like in Verizon iPhone, you have to inject the phone number.
It's definitely iPhone 4G. I think that iPhone 4G will come out this summer (AT&T ONLY), follow by a January release on Verizon. This is why, iPhone going to Verizon will not impact AT&T as much. At least I think so. We won't see "iPhone 5" until Summer of 2012. THAT'S MY PREDICTION. I think if I'm right, iClarified should give me a prize or something lol.