Right now Warriors are the best tanks. Druids can tank pretty well, but Pallys are pretty much useless end game (unless your guild is really cool) in Pvp and pvE unless they are healing.
I don't believe in gender roles, all Pallys need is a taunt, which I believe was patched in before BC. I know crusader strike is BC, but i think Pallys would be much more viable as tanks if we had something that helped pull aggro back to us.