Unlike prior releases of Apple’s iOS operating system for iPod touch, iPhone, and iPad devices, the iPhone 3G and second-generation iPod touch were notably absent from the list of devices for the beta version of iOS 4.3. While no official announcement has been made on the subject, it is likely that Apple has decided not to release further OS updates for the two devices, which previously missed out on key features added to iOS 4. The iPhone 3G…