With my DK in tank spec, and the best "tank" gear her DPS set allows, I started collecting all the true tank gear I could get my hands on easily.
Using this EJ list I got all the reputation gear, as well as non-epic gear purchased, gemmed and enchanted. And landed with just over 500 defense. Mmmm :(
Need 40 more to get defense capped to be un-critable by bosses. I'll need to run some heroics for badges, and hit HOL for the trinket!
On a related note, my Druid is doing every effort to join the Wintergrasp battles each time they occur, to get 40 badges she needs for her tank head piece.