Select up to 2 answers.
Another alchemist, to have more than one spec.
And, also, it depends on what kind of druid, and whether you are raiding. Herbalist with flight form in awesome! I kept mine, even though for a resto druid lifebloom is utterly useless, because I love herbing on her. Lifebloom is more useful for ferals, but I still wouldn't suggest it as an ideal tradeskill for a raider. It just doesn't live up to the other bonuses out there. If your druid isn't going to raid, then either skinning or leatherworking and whatever skills you are missing.
I have all the professions and while I've no idea what it will be like in Cata, LW is my least favorite. It was fun for a little while but now I find it frustratingly pointless. Quest rewards are frequently better than what I can make so that when I hit 78/80 with a new alt there's not a lot to be made for upgrades. Either quest rewards are close or buying BoEs gives me a much better item for not much cost. Druids are the best double gatherers and while mining is great I love the skinning/herbing combo because you never have to shift out of flight form.