On live realms, the training dummies found within the garrison often prove to be a problem for DPS players. With the tanking dummy standing right next to the damage dummy, any sort of splash or cleave damage -- a baseline part of many DPS rotations -- hits the tanking dummy which proceeds to kill the player. The issue renders the dummies effectively unusable for many players who might be interested in practicing their rotation.
On the patch 6.1 PTR, the damage and healing dummies have swapped places. The tanking dummy remains on the far left and the damage dummy is now on the far right. Even if you accidentally hit the tanking dummy with a bit of AOE damage, you're standing far enough away that you won't be brutally murdered by an ostensibly inanimate object.