As a Druid, we can't tank everything, there are some bosses that fear, and well that is when you need the Warrior.
I am Feral, and the Group I roll with also has a Priest, Mage, and Warrior. We have a 5th spot that we fill as needed.
Between having 2 DPS, 2 Tank, 2 Healer and a Filler spot to add as needed, we are pretty good to go for just about anything.
It really depends on the people with whom you group, but Druids scale better than other classes from levels 1-70, because they get more abilities as they level in comparison to other classes. I wouldn't trade my Druid for any other level 70 Class even if it was a max gear and unlimited gold filled Warlock. lol
Edited, Apr 5th 2007 7:05pm by Ephen