For most of vanilla WoW and Burning Crusade, my main was a Druid. I healed, I tanked, I DPS, I raided, I PvPed, I did everything with him. He was a great character, I found the class fun (Yes, even before patch 1.8, thank you very much). But somewhere around mid-Burning Crusade, I just plain burnt out on Druids. I don't know if it was just one too many bad raids, if it was just familiarity breeding contempt, or what, but I switched to a Hunter and never looked back.
When Death Knights were announced, I knew that was my new class, and I also knew that my Druid was probably doomed to be level 70 for good. I'd focus on my Death Knight, then my Hunter, then probably my Shaman for heals, followed by my Warlock. My Druid would just languish in Shattrath unless I was really, incredibly bored.