This is a quick writeup to help you to know right away where you want to focus your questing so that you have the reputation you need when you hit level 85 to get your head and shoulder enchantments. Yes, you can only apply these at level 85.
Same - Just like Wrath of the Lich King, you will be able to pick up a tabard once you are friendly to further your reputation gain while running heroics.
Different - Unlike Wrath of the Lich King, the "Lesser" Shoulder enchantments are not equivalent to the previous expansion's "Greater" enchantments. Not only are the secondary stats a bit different due to the new features of Cataclysm, but the actual stat bonus is a bit larger as well.
I'll begin with the head enchantments. The cost appears to start at 150g, but of course by the time you're revered that cost goes down to an amount equal to 120g, I think - possibly 135g at revered and 120g at exalted.
Mount Hyjal (Kalimdor) 78-82
Quartermaster is found in Nordrassil
Revered with the Guardians of Hyjal
Arcanum of Hyjal: 60 Intellect & 35 Critical Strike Rating
Vashj'ir (Eastern Kingdoms) 78-82
Quartermaster is found in the following path:
Shimmering Expanse -> Shimmering Grotto -> Silver Tide Trench -> Silver Tide Hollow
Revered with The Earthen Ring
Arcanum of the Earthen Ring: 90 Stamina & 35 Dodge Rating
Uldum (Kalimdor) 83-84
Quartermaster is found in Ramkahen
Revered with Ramkahen (Cat people)
Arcanum of Ramkahem: 60 Agility & 35 Haste Rating
Twilight Highlands (Eastern Kingdoms) 84-85
Quartermaster is found at the Bloodgulch
Arcanum of the Dragonmaw: 60 Strength & 35 Mastery Strike Rating
Next up, Shoulder Enchantments. All of these can be found at Deepholm in the Maelstrom. The Quartermaster is located at Therazane's Throne. From what I could tell, they are all 60g. Deepholm is a level 82-83 zone according to wow wiki.
The following are the shoulder enchantments for honored reputation:
Lesser Inscription of Charged Lodestone: 30 Intellect & 20 Haste Rating
Lesser Inscription of Jagged Stone: 30 Strength & 20 Critical Strike Rating
Lesser Inscription of Shattered Crystal: 30 Agility & 20 Mastery Rating
Lesser Inscription of Unbreakable Quartz: 45 Stamina & 20 Dodge Rating
The following are the shoulder enchantments for exalted reputation:
Greater Inscription of Charged Lodestone: 50 Intellect & 25 Haste Rating
Greater Inscription of Jagged Stone: 50 Strength & 25 Critical Strike Rating
Greater Inscription of Shattered Crystal: 50 Agility & 25 Mastery Rating
Greater Inscription of Unbreakable Quartz: 75 Stamina & 25 Dodge Rating
And yes, this faction does include a tabard at friendly for heroic reputation runs.
Now, I'm not sure why the Arcanum of Dragonmaw says "mastery strike rating" while the shattered crystal ones say "mastery rating." I don't know if that is something specific with that type of melee dps or just a inconsistency or error of some sort. Also, this information is from the Beta, so it is subject to change. But I wanted to share this to give everyone an idea of where to start/focus questing. And of course, each quartermaster also has gear you can get as you level up so check that out as well. Totalhalibut goes through each item at every quartermaster in the video I linked above.
