I worked in the domestic violence field for many years, and physical violence is NEVER acceptable--and even aggression is violence. You did exactly the right thing by calling the police.
I can guarantee you he will be remorseful and make more promises. Unless he gets help (with the alcohol AND the violence--they are related but separate issues), you can expect this to continue, only worse.
You have a window of safety with him in the hospital. Whether you file for divorce is not a decision you need to make immediately, but you CAN insist that he not live with you until you are satisfied it is completely safe.
My strong suggestion would be a domestic violence restraining order. Suki is right, this is scary and damaging to your children. Kids are better off with one parent who financially struggles than two parents in a violent home.
Please take care of yourself and the kids.