As a reminder, here are the two tweets he sent out in that position:
Al Quds al Arabi is reporting that Hamdallah has apologized for his hasty resignation, and Abbas is considering allowing him to continue on as prime minister.
I believe that he has been the caretaker prime minister since his early resignation, meaning he has been a caretaker PM far longer than he was actual PM.
Meanwhile, the last prime minister, Salam Fayyad, has been active on Facebook, acting as if he is not out of politics at all.