Network multiplayer is working, kinda.
I'd planned for it from the beginning and implementing it required me to rewrite only a few minor things. The Lidgren library does most of the work with delivering packets.
The video shows a battle scene that I've used in previous videos. It's the berserk AI playing against "Tactician". A few tweaks are necessary to allow a human to play. This is because identifying a unit's ownership is very primitive. If the owner value is "player", then a human controls the unit. Thus both players would attempt to control the same unit.
The lobby system has few features at the moment. The player list and a "Start" button are the only things working. Scene/battle selection is hard coded.
The overall structure is pretty frail as I've not built in any fail safes. But whatever, I've seen AAA games that are worse.