Midway has officialy announced the complete cast of characters for Mortal Kombat vs. DC Universe:

Mortal Kombat

• Scorpion
• Sub-Zero
• Sonya
• Jax
• Shang Tsung
• Liu Kang
• Raiden
• Kitana
• Kano
• Baraka
• Shao Kahn

DC Universe

• Batman
• Superman
• Catwoman
• Green Lantern
• The Joker
• Shazam
• The Flash
• Wonder Woman
• Deathstroke
• Lex Luthor
• Darkseid

Source – Daily Game