Some considerations on alternate Shadow-oriented specs:
More Yin than Yang 00/30/31
More Yang than Yin 00/36/25
Aside from the all-out DPS Shadow offers, the main points of Shadow to keep in mind are:
• Shadow Weaving for increased damage from Shadow (IE: Warlocks)
• Vampiric Embrace for supplemental healing!
• Vampiric Touch for supplemental mana regeneration!
• Silence for... well, silencing!
• Shadowform for increased damage and additional soaking ability!
Shadow is not just a guilty pleasure, this spec has taken a viable hold in 5-man and raids alike. Though the specs above don't include Vampiric Touch, the mana regeneration it provides can rival that of a Mana Tide Totem.
One consideration might be to rearrange points into a 5/5 Shadow Focus. This will reduce the chance of resisting your Shadow spells (IE: Mind Control).