Tanking for Druids

Of course druids are a
highly versatile hybrid class,  but sometimes you want to maximize your ability in a single area.  And in this case knowledge -
knowing what you want to do and how best to accomplish it – is power.  With this in mind, I present Alterreality's
excellent post
with regards to bear and warrior tanks, which is full of hard, numerical data and clearly shows a druid's strengths in tanking (high HP and armor) and weaknesses (lack of available leather defense gear, inability use shields, etc). 
Overall, it sounds like a warrior's access to defense gear (reducing critical strikes against them) starts to be more and more beneficial on more and more difficult bosses, making them the only obvious choice for end-game content. 
What do you think – can druids hold up to the tanking ability of a warrior?