Two clever players have already discovered some exploits with the day one DLC characters in Tekken Tag Tournament 2 that are not game-breaking, but will probably be patched by Namco in the future.
Canadian player thegutsygeek has uploaded a video showing how Kunimitsu's crouching hitbox is small enough to dodge certain mid attacks. Here's what he had to say about it.
Here's a short list of what we found after about 5 minutes of testing. It's worth noting that these moves don't whiff on any other crouching character.
King: -f+4 -JGS df+4 -WS+1 -1+2
Armor King: -f+2,1 -f,f+4
Bruce: -WS+2,1 -df+2
In the second video, DR1013 demonstrates how Ancient Ogre's Infinite Kick can combo an opponent indefinitely. Aris from Avoiding the Puddle has confirmed that it is an actual infinite in his post here. Unfortunately, this is what happens sometimes with console exclusive characters that don't get the extensive testing required to balance them properly.
Check out the videos following the jump.