In order to balance professions in Wrath of the Lich King, Blizzard has tried to make profession perks equal, because players tended to reroll to the most beneficial professions in the past. To prevent this the bonus gained from a profession is similar most of the time, although there still are some minor differences.

Jewelcrafters are able to cut unique epic gems. Three of these gems can be socketed into the players equipment. These gems are stronger than the ordinary gems and make achieving socket- and meta-requirements much easier.

A blacksmith is able to add additional sockets into his bracers and gloves, which will provide a nice boost once the right gems are socketed into these. This perk provides a lot of flexibility, making it especially interesting for a Paladin. Enchanters are able to enchant their rings - a perk they already had in the Burning Crusade. The enchants have gotten stronger though. Leatherworkers are able to imbue their bracers with special fur linings, which is way more powerful than an ordinary bracer enchant - and much cheaper as well.

A scribe is able to craft special shoulder enchant. These are not only more powerful than their Sons of Hodir counterparts, but you can also skip the annoying reputation grind there.

Tailors and engineers are left in the field though. While a tailor is able to imbue his cloak with a special kind of embroider the effects are of little use to a Paladin, regardless of spec, making the ordinary cloak enchants more powerful. Not a big deal, since hardly any Paladin was tailor anyway. Engineers are able to create special gadgets which they can add to their belt or gloves. Those are less effective than the regular enchants for these slots.

An alchemist gets the ability "Mixology". This makes elixirs and flask last for twice the time and have an increased effect.