There was a pretty big outcry about this, and understandably so. The Burning Crusade has made Stamina a very important stat in all areas of gameplay from PvE to PvP. You need to be able to take blows in the arenas, and almost every raid encounter has multiple sources of random damage to the raid. Stamina is a big deal, which brings us to the good news.
The Stamina has returned to the T6! Not in the amounts it had previously(unfortunately) but still a decent amount. While not ideal, it has enough Stamina that classes can actually wear these set pieces now. Previously, with no Stamina on this armor, most classes were completely unable to wear them in a raid. I know that I, personally, already have to wear PvP gear for a number of encounters because my raiding gear simply doesn't have enough Stamina on it for Black Temple and Mount Hyjal. New tier pieces with no Stamina at all would be something I could not even consider using, no matter how good the rest of the stats may be. Being one-shotted by environmental damage makes that awesome damage and mana regen a little useless.