Again, crafting is being made not as a replacement for loot, but more as bad luck protection from what it seems. Also, if an alchemist can do a trinket that scales up to top ilvl, depending on the proc it can easily become BiS for someone. It really all depends on balancing.
Weapon/trinkets are usually the biggest dps increases. Also was mentioned how the new "craft your tier" idea could be easily baked into professions because it just makes sense and both keeps them relevant longer ad removes the need to create a new "tier forge with a new name and an arbitrary currency" each patch.