Wrath of Lich King Profession

In Wrath of the Lich king the professions will be even more unique as
they will not only give you new recipes but some will also grant you certain "bonuses".

I have listed these bonuses and some new recipes/abilites to help you choose
the right profession(s) to stick with in the upcoming expansion.

Alchemy:
Mixology (passive) - Increased effect and duration of elixirs or flasks but only from those that you are able to make.
Crazy Alchemist's Potion - "Heals, replenishes, or does something else... depending on the situation." Whetever this is good or not can be discussed.
Endless Healing Potion (BoP) - Restores 1680-2160 HP. Has a 3min cooldown.
Endless Mana Potion (BoP) - Restores 400-600 Mana. Has a 3min cooldown.

Blacksmithing:
Socket Gloves - Adds one socket to a pair of gloves. Can only be used on own armor and binds the gloves to you.
Socket Bracer - Adds one socket to a pair of bracers. Can only be used on own armor and binds the bracers to you.

Enchanting:
Enchant Ring - Assault - Increasing Attack Power by 32. Only usable on the master-enchanters ring(s).
Enchant Ring - Greater Spellpower - Increasing Spell Power by 19. Only usable on the master-enchanters ring(s).
Enchant Ring - Stamina - Increasing Stamina by 24. Only usable on the master-enchanters ring(s).

Engineering:
MOLL-E - Portable mailbox - Creates a portable mailbox for 5min. Has a 24H cooldown.
Scrapbot Construction Kit - Creates a vendor that buys anything. Serves for 5min and has a 15min cooldown. Comparable to Field Repair Bot 100G.
Wormhole: Gadgetzan - Creates a wormhole that should teleport you and your current party to Gadgetzan.
Gnomish Army Knife - A knife? No. This spell has a chance of chocking a dead player back to life. Cannot be used while in combat and has a 30min cooldown.

Inscription:
4 Shoulder enchants - Can only be applied to the inscription-masters armor and will cause it to become soulbound.
Decipher - "Allows the dechipering of a strange and mysterious writing". Some people believe this is used like the Rogues Lockpicking, only that it "decrypts" a scroll.
Runic Blast - Blasts an enemy for 24-30 Arcane damage.Consumes Ivory Ink when used. Whetever there is a higher rank of this spell is so far unknown.

Jewelcrafting:
18 Bind-on-Pickup gems - Can only wear a maximum of 3 Dragon Eyes.
Figurine - Emerald Boar (Trinket, BoP) - One of the four new trinkets available to JCs only.

Leatherworking:
4 Leg armors - Can only be attached to the master-leatherworkers own armor and doing so will cause the item to be souldbound.
Fur Lining - Can only be attached to the master-leatherworkers own bracers and doing so will cause the them to be souldbound.

Tailoring:
3 Cloak embroideries - Can only be embroided on the tailoring-masters cloak and will cause it to become soulbound.
6 Carpets (mounts) - Can only be used by the tailorer.
A Guide to Northern Cloth Scavenging - Using this will increase the chance to find cloth on Northrend humanoids


Gathering professions

Herbalism bonus:
Lifeblood (Rank 1-6) - A HoT-spell that will scale with your herbalism skill and heal you for 300-2000HP over 5 seconds.
Fire Leaf - Reduces your armor by 100%, but increases your attack power by 400 for 10 sec. Has a 1min cooldown.
Fire Seed - Makes you vulnerable to magic, but increases your spell power by 200 for 10 sec. Has a 1min cooldown.

Mining bonus:
Toughness (Rank 1-6) - Will increase your maximum health by 30-500HP.

Skinning bonus:
Master of Anatomy (Rank 1-6) - Will increase your critical strike rating by 3-25, 0.54% at level 80.

Sources
wow profession guide
wow-wiki