Thanks to the information slowly (we just can't get them fast enough around here...) leaking out from the Wrath of the Lich King Beta, we already learned that the professions trend started in The Burning Crusade will continue in the new expansion. The Burning Crusade (or Patch 2.0) introduced new items or enchantments that confer bonuses exclusively the character with the profession, such as ring enchants for Enchanters or Bind-on-Pickup gems for Jewelcrafters. This was a welcome change that rewarded players with their choice of profession -- almost to the point where such profession-only bonuses compelled many to choose professions somewhat incongruous with their class.
Hardcore PvP players pursued Enchanting for the ring enchants, for example, while hardcore raiders leveled their Leatherworking for the Drums of Battle. In Wrath of the Lich King, the different professions get even more exclusive goodies designed to keep professions more or less in tune with their intended classes. Eliah reported about the passive buffs for gatherers, and they seem to be in thematically tuned to some classes. Take Master of Anatomy, for example, which seems to be a benefit given to Skinners. Traditionally, Rogues, Hunters, and Shamans were the classes who pursued Leatherworking and its complementary profession, Skinning. The passive benefit to critical strikes are certainly welcome to those classes, so players who chose to stick to their Skinning will actually receive a pleasant boost in Wrath.