To really integrate, Woodworking would need to use other materials, and other professions would want to use wood.
Woodworking could utilize Skinning, which would fill another hole in WoW. Herbs are used by two professions, Mining by three, and Skinning by one! But hides could be stretched over framework to create portable lawn chairs, rolled into strong strings for bows, used to hang carvings, construct bags/boxes, cover or line items, and more.
Scribe inks could be used to make paints (by either Scribes or Woodworkers, or even transmuted by Alchemists) that could decorate or imbue objects.
Wood could be used in wand creation in place of vendor woods for Enchanters and enchanted to make special woods used in crafting. Pulp, as a by-product of Milling, could be used in the creation of better papers by Scribes. Engineers would certainly have plenty of uses for wood, and Tailors and Leatherworkers could probably find a use as well.
Sap, as a by-product of Logging, could be used as an adhesive, flavoring in Cooking, mixed into certain inks, or go into potions, elixirs and flasks. Dust, as another possible by-product, could be sold to Enchanters. Roots could be dug up and used in Cooking.
Alchemy oils could be used as finishing coats on many items. Metals could be used for hinges, uncut gems for decoration, disenchantment materials could be fused into things, and much more. Pick anything that isn't used enough, or end-game materials that need to become more scarce, and use your imagination.
Engineers could create a new gadget that combine the Logging axe and shovel, as well.
Whether this balance would be achieved by modifying reagents from older recipes, or creating new ones (likely both), it could be done.
Nethaera also mentioned that art concepts are important when adding a new profession. I think that Native art elements, as well as Troll-esque art, rune-like images, Pioneer styles and "primitive" elements would be quite welcome.
The story behind it all, and the next expansion
So who would bring this craft to the masses? Why, the Venture Company of course! Well, ex-Venture Company. In the next expansion, if Goblins do indeed become playable, we can expect that the (likely Horde) Goblins will have their own story, and of course, the neutral Goblins wouldn't be left out of this development. Some Venture Company members could have defected and found a home within neutral boundaries.
Eager to prove/redeem themselves, and make a little coin of course, they will pass along their most valuable skill; that of gathering, transforming and creating with, wood. Trainers could show up in Ratchet, making them accessible to young Trolls, Orcs and Tauren, in Booty Bay to be more accessible to some Alliance, and later, in other neutral Goblin towns.
In addition, in towns that contain a Goblin or two, an ex-Venture Co. member could be tagging along, able to reach out to small Horde and Alliance outposts, selling their know-how while the Goblin sells wares. This could even be an opportunity for a new Goblin faction that would grant reputation, although you might think that it is they who really owe us a reputation grind!
Later, in the sanctuaries of Shattrath and Dalaran (perhaps in the sewer), neutral ex-Venture Co. would be free to set up shop in peace. Not all of these NPCs would need to be Goblin, as there are plenty of other races in the Company, but the new playable Goblins could indeed get a profession-related racial.
CM Drysc has also hinted that we haven't seen the last of the Venture Trading Company, making all of this seem even more plausible.
As a point of interest, in Wrath, several Tailoring patterns were added for Lumberjack and Workman shirts. Could this have been a hint of things to come, or merely a questionable fashion choice?