There are 8 new Trophies in this DLC.

BRONZE

Let's Get a Rally Going!
Rally 50 iconic allies in Assault: Headquarters arena matches

Making a Name for Yourself
Knock out 50 iconic enemies in Assault: Headquarters arena matches

Putting the Safe Back in Safehouse
Win 100 Assault: City Safehouses arena matches

SILVER

Space Invader
Unlock Ursa, Power Girl, Amon Sur and Kilowog Legendary Battle Arena Avatars

The Armor Makes the Man
Collect all styles for the Knight PvP Battlesuit

Knight Moves
Collect a complete Checkmate PvP Battlesuit

Together We Stand
Complete the Assault: Headquarters arena match without letting any iconic allies get knocked out

This House is Clean
Complete the feats: My Life as a Robot, Hostage Negotiator, and Spacial Delivery

http://www.ps3trophies.org/game/dc-universe-online/trophies/