Yesterday I tried updating 6 apps but my iPad crashed and restarted almost immediately. Since the these three apps are in state waiting, icons greyed out and an empty progress bars. I have rebooted the iPad, no success. I have removed the apps and replaced them via iTunes, no success. Today another app update was available that installed normally, the other six are still "waiting". My next step would be to recover to an old backup or something, but before that I am posting this thread to maybe get a less dramatic solution.