BGs and tanks - worth it?

Hey guys!

I wanted to roll a tank for bgs, and I was wondering, are tanks even worth it atm in MOP?

The way I see it a tank does very little damage compared to DPS classes, and still gets rekt somewhat quickly without a healer. Am I wrong here?

Also, in 5.2 patch Blizzard made tanks suffer 50% extra damage while they carry a flag / orb in battlegrounds. How big of an impact does this carry?

Is the better option for bgs to roll a tank spec, or roll a DPS spec and gear it a little tankier?

Whats your opinions on these points?

Thanks in advance for replying!

Regards, Demonheim