Elemental Shaman enchants

Update: For Wrath the enchants are obviously different, but they are generally upgraded versions of the old TBC enchants.

• Legs - Sapphire Spellthread. Quite expensive so I may well go for the cheaper Azure Spellthread.
  
• Bracers - Superior Spellpower.
  
• Gloves - Exceptional Spellpower
  
• OR I have seen Gloves - Precision. I guess you could take this if you have low hit rating or the Spellpower is a little expensive.
  
• Chest - Powerful Stats. This is good due to Shaman stat conversion (from WoWWiki) adding mp5 and critical chance, plus more mana.
  
• Main hand weapon - Mighty Spellpower. This is a tasty enchant but quite pricey, so consider Exceptional Spellpower.
  
• Shield - Greater Intellect. All the other shield enchants seem to be for melee types.
  
• Boots - Icewalker. I have one with movement speed increase for my hunter, which is very useful for fights where you have to run around a lot. But the movement enchants have either +stamina or +agility, neither of which seem to be highly useful to a spell caster.
  
• Cloak - Greater Speed. Threat is no longer an issue (shouldn't be anyway) so haste wins.
  
• Head - Arcanum of Burning Mysteries (Kirin Tor - Revered). Oh dear, this involves running a lot of Heroic in general.
  
• Shoulders - Inscription of the Storm or the Greater versions.
  

TBC post for history
For some reason, the Elitist Jerks Elemental Shaman wiki doesn't list enchants to grab, which isn't too helpful as my Elemental gear is mostly unenchanted, due to a potent combination of laziness and not being prepared.

Luckily we have an uber Elemental Shaman in our guild from who I can steal the following list of enchants I really should get. This is for a PvE Elemental Shaman, as I have seen resilience and stamina on PvP Shaman's gear.

• Legs - Runic Spellthread (10 Primal Mana, 1 Primal Nether). Quite expensive so I may well go for the cheaper Mystic Spellthread (5 Primal Mana).
  
• Bracers - Spellpower (6 of each Large Prismatic Shard, Primal Fire, Primal Water).
  
• Gloves - Major Spellpower (6 of each Large Prismatic Shard, Greater Planar Essence, Primal Mana)
  
• OR I have seen Gloves - Spell Strike (8 Large Planar Essence, 2 of each Arcane Dust, Large Prismatic Shards). I guess you could take this if you have low hit rating or the Spellpower is a little expensive.
  
• Chest - Exceptional Stats (4 of each Large Prismatic Shards, Arcane Dust, Greater Planar Essence). This is good due to Shaman stat conversion (from WoWWiki) adding 3.4 mp5 and approx 0.1% spell critical chance, plus more mana.
  
• Main hand weapon - Major Spellpower (8 of each Large Prismatic Shard, Greater Planar Essence). This is a tasty enchant although ideally there would be an enchant for +50 nature damage, similar to Sunfire.
  
• Shield - Intellect (4 Greater Planar Essence). All the other shield enchants seem to be for melee types.
  
• Boots - Vitality (6 Arcane Dust, 4 Major Healing Potions, 4 Major Mana Potions). I have one with movement speed increase for my hunter, which is very useful for fights where you have to run around a lot. But the movement enchants have either +stamina or +agility, neither of which seem to be highly useful to a spell caster.
  
• Cloak - Subtlety (4 Small Prismatic Shards, 2 Greater Planar Essence, 8 Primal Shadow). As Andrew points out, threat can be a real issue for high-critting Shaman, so this enchant is well worth the primal shadow.
  
• Head - Glyph of Power (Sha'tar - Revered). Oh dear, this involves running a lot of Tempest Keep instances. Still, it's pretty nice.
  
• Shoulders - Inscription of the Orb, Discipline or the Greater versions. You could take the 5 mp5 inscription from Scryer if you are short of mana regeneration, but I prefer critting things.
  

What does all this add up to? Taking the Mystic Spellthread, Inscription of the Orb and Major Spellpower on gloves, we get 122 spell damage, 0.8% spell critical chance, 7.4 mp5 and 14 spell hit rating. Consider that my blues-and-greens Shaman has around 400 spell damage, that extra 122 is pretty nice, so I really ought to get some enchants done.

What if I have a green item in a particular slot, should I bother enchanting it? My approach is that if the enchant/inscription is cheap, I'll get it done, because it won't cost me much when I replace the item. Whereas something expensive like Major Spellpower won't be put on my Talbuk Sticker.