It would appear that Rainbow Six: Patriots is alive, but now has a new name.
Before the Ubisoft Press Conference concluded they showed the much sought after new Rainbow Six shooter now called Rainbow Six: Siege. Years ago, we were shown that a game called Rainbow Six: Patriots existed, Though it seems now the game may have switched focus.
We were shown a 5-on-5 match in Rainbow Six: Siege's multiplayer where a team was assigned to rescuing a hostage, while the other team had to keep her. The rescuers had to choose where to enter the house while remaining in constant contact with each other about their movements, what/who they saw and how to handle a situation.
During the match, players used environmental destruction and breaching to their advantage as they tried to rescue to the hostage. Ubisoft also wanted to show that the hostage is not just a "flag" to capture as they can be hurt and you must heal them if they are shot.
We'll learn more about this tactical shooter when it becomes available.