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). Speculate all you want, but there isn’t much else at all we can say definitively here, but if we had to take a guess, it’s the GSM and CDMA variants of the next-gen models (plus a WiFi-only iPad). It is interesting to note the lack of an “iPhone4,3” given the yet-to-be-revealed iPhone3,3 is still there — will the last member ever see the light of day?
It looks like these references point to the GSM and CDMA version of the iPhone as well as the Wi-Fi, GSM and CDMA iterations of the iPad, however we do know that the next generation iPad and iPhone is likely to come without the home button and will be controlled via multi-touch gestures, only the future will tell what will become of the devices mentioned in the code.