Quote:The main tank is the one who gets all the glory (so to speak). Tanking adds does not require the same quality of gear either, so if you have someone who's constantly off-tanking but doing other jobs as well, he probably won't upgrade his gear anywhere near as much as the main tanks (which will effectively ensure he'll never do anything but off-tank).
And there are encounters without off-tanking where this doesn't even apply.
A good raid leader will make sure that upgrades are spread around evenly. I speak from the experience of losing a 8/8 wrath warrior MT to burn out.
Edit: And as a present MT more often than not I can tell you that the glory doesn't go to us but to the team.
The one time I really "shone" as a warrior was when I picked up Nefarion after the MT died and managed to shield wall the last 2% with the only healer on fumes.