In Blitz Mode the objective of the team is to attack and defend portals. Each team has a portal which they must defend or fight to enter. Enemies who enter the portal score points for their team and are teleported back to their portal spawn points for defense and the portal they scored upon shuts down temporarily to prevent a stream of players entering a portal.
Like Demolition this game mode will certainly be a spawn killers delight since enemy spawn points will be more predictable. Blitz also utilizes delayed spawns similar to Capture the Flag. Blitz hopes to create a greater reason to play as a team but given the history of Demolition mode its clear that spawn killing will be the real focus for strong teams.