In the most recent beta push, patch 8885, training dummies were added to the sewers of Dalaran (and many other places in the world as well, apparently) by popular request. They were requested to replace what Dr. Boom did for everyone in The Burning Crusade: A way to benchmark DPS and crunch other numbers while outside of a raid, on a mob that didn't die long before you hit your limit. These training dummies certainly helped, but there was only one problem. The dummies were level 1, so certain important stats were greatly inflated while hitting them, such as critical strike percentages.
Luckily, Kalgan has posted that the training dummies will be getting an upgrade in the next patch. The level 1 dummies will be replaced by level 80 dummies with typical level 80 stats, as well as 'boss level' dummies with boss stats. This will definitely provide much more accurate numbers for players trying to benchmark themselves. I, for one, look forward to testing the upcoming Shadow Priest changes on one of these as soon as it's all in place. I do not, however, look forward to searching for a dummy not already in use by someone else! They've been insanely popular on the beta realms in their level 1 state, and I think beta testers will love them even more at the proper levels.