#1 - June 5, 2014, 8:46 a.m.
Blizzard Post
Those in our Beta will immediately notice that the stats on your gear, as well as your base health, have been scaled down as part of our broad "stat squish" that we have previously discussed.

All content in Draenor is currently suited to these new values, and Siege of Orgrimmar has actually been converted to use the new raid structure (since I know that the absolute first thing everyone will want to do upon getting access to our Beta is to go run Siege). But if you find yourself in any other locations in the old world, beware that while creature health and melee damage has been "squished," the damage values of their abilities/spells has not yet been. So a yaungol's Fireball that used to hit you for 50,000 still hits you for 50,000. (But you of course have far less health now.)

We're making sure that we're completely happy with the state of numbers before taking the final step of locking in those values for all old content, since it's a lot of data to touch. So in the meantime, if you decide to do something like visit Timeless Isle, or Throne of Thunder, or other pre-Warlords content, it will not go well for you. But please don't be alarmed or concerned that you'll be unable to do older content as a result of the squish. The current state of affairs is temporary, and we'll let you know once Azeroth has been fully updated to reflect the new stat values.