In World of Warcraft if you want to find a group, roll a tank. Tanks are hard to find and good tanks are worth their weight in gold, even Tauren tanks. Goosesausage of Cenarius posted some suggestions he believes might resolve the current lack of meat shields. He suggests that non-protection specialized Warriors would be capable of tanking if the Sunder Armor buff was tweaked a bit.
The poster reported that he has a hard time finding heroic groups since his warrior character is currently specced for DPS. To resolve this issue, Goosesausage suggested that removing the cost of changing one's specialization might resolve the issue. I both agree and disagree with this suggestion. True it's pretty expensive to switch back and forth from prot to DPS and back regularly, but thanks to daily quests money is not nearly as short as it once was. Just make sure you do your grinding before you spec to prot. Even if there was no respeccing fee, tanks would need to acquire two sets of gear.