I finished a bare-bones RTS game for the TIGSource Versus Competition which was built with Unity and Player.IO. The game itself is simple and not very polished, but it has multiple units types and a randomly-generated map, which I thought was pretty cool. The game centers around "mustering" creatures by reaching various muster points around the map and then using those creatures to attack other players.
You can play the web version if you download the Unity Web Player: Web Player Version
Windows and Mac executables are posted in the original TIGSource thread.