Not even close
They do not have snap aggro, they do not have the aggro generating abilities that warriors have. They don't have sustained threat generation (mana decreases, rage is infinite) and they do not have the damage reduction as warriors do (defensive stance).
Most importantly, they don't have the gear, especially when compared to warriors end game. Sure paladins can get high armor and a decent amount of stamina, but warriors can push 420+ defense with 25% block, 15-20% dodge/parry as well as 7k hp.
In 40 man raids, especially BWL and AQ, you will see that paladins are heal bots, and their biggest contribution are their blessings. But when you see fights like the Twin Emperors, which is 15 minutes in length, on average, you will see that they simply do not hold a candle to the abilities of a warrior.
Druids on the other hand have the ability to tank nearly as well as warriors. Their strengths are highest armor (15-16k), very high hp (7k+) and decent threat generation. However, their biggest weakness is the inability to handle fear, crits, and lack of parry.