From what I understand this vote will give Palestine the ability to take Israel to the war crimes court.
So Hypothetical:
They go to that court and Israel or an Israeli citizen gets convicted. The UN asks that he be handed over and Israel gives them the bird. Then what? Let's say that that person goes to the U.S., Canada or Germany (all countries against this vote). Does that country arrest him? What if they refuse? What does that do for any attempt at UN legitimacy?