Preparing for Wrath of the Lich King

Tobold's MMORPG Blog discusses preparations that can be taken to get yourself ready for Blizzard's World of Warcraft: Wrath of the Lich King expansion pack.
While metals and gems were certainly things I don't foresee needing in WotLK, cloth and herbs are a different story. Death Knights start out with 270 in First Aid, and will need Runecloth and up to train that skill further. And anyone trying the new Inscription profession will need tons of herbs of all levels. I think many people already stored the lowest level herbs in abundance, and most alchemist have stock in Outlands herbs. But the mid-level herbs could suddenly become extremely expensive on the auction house, and gathering those, or buying them for cheap when available, could be a great money-making opportunity. I'm not 100% sure about enchanting supplies, but the new ability to put enchantments on scrolls and sell those could also increase demand a bit there.