The Apple Watch lacks a cellular baseband radio, and it's battery life is a big question mark. What if it gained cell phone capabilities and had a battery large enough to last more than a day under heavy usage? This would require significant advances in miniaturization and battery capacity. The watch could be used as the phone, and iPod touch could rise again as a device that tethers to the watch for situations where one needs a larger screen. Could Apple Watch kill iPhone and resurrect iPod?