I was also on this flight, but was sitting upstairs so I missed the action. Here is what our flight attendant told us:
1. Passenger made a new friend with the female passenger sitting next to him and the two of them decided to have some fun.
2. Passenger eventually asked for 2 glasses of wine but was refused. When she refused to serve him, he slapped her.
3. Passenger took off his pants and threw them on the people in the row behind him. His pants were soaking wet.
4. The captain was called in and while talking to this guy, the guy asked the captain what he was going to do because of his behavior. He went on to challenge the captain to a fight. The captain left and instantly made the decision to divert.
5. As already mentioned, the Captain told us on PA we needed to stop for fuel in Anchorage. It wasn't until after the passenger was removed that the Captain told us the details.
6. We were only on the ground for around 45-60 minutes. After we took off, everyone was assured of making their connections.
7. Instead of waiting until the end of the flight, we were served breakfast not long after leaving Anchorage.
All in all I thought the situation was handled very well, although I'm surprised this guy wasn't ever physically restrained by anyone. It was amazing we were able to get out of Anchorage so fast and that no one missed their connections in NRT. We were also informed of the incident. I was very pleased with the Captain and his staff.