Druids have quite a span of options for secondary classes. Preferably I have found that D/S has some of the best healing ability, and D/W has a nasty elite (Awakening of Warrior) which is currently the best buff for your physical DPS (Rogues, Warriors, Scouts, Etc..) I do also know that D/Wd is prefered for survival also. But in this situation I guess you need to ask yourself; are you going for all out healing, party support, or survival... Either way you cant go wrong. If in doubt, check out the elites each one would offer you and make your decision!