I don't think so. The iPhone was revolutionary because suddenly you had a lot of sensors and the power to use them in creative ways. There are still sensors that could be added to devices of this price range that, coupled with new apps, would make them cool again: infrared vision, range finder, molecular scanner, etc.

Imagine pointing your camera to find an A/C leak inside the wall, or scanning fruit for their ripeness, or measuring furniture at the store to see if it fits in your house/door. Hell, it could even alert you if you have bad breath.