Well, been messing around with assorted lock builds on TBC, think I came up with two I sorta like (keeping in mind I do not PVP):
If the Fel Guard is worth a damn:
Demon Build
Demonic Embrace (15% +STA)
Demonic Resiliance (4% chance to avoid Crits)
and +15% dmg if I have my succubus or fel guard out
Supposidly the fel guard is a real tank vs. our blueberry speedbump
If the fel guard sucks (a distinct possibility concerning Blizz's track record with upper level pets):
Destro Build of Doooooom
Crit Strike chance of destruction spells +5%
Crit Strike dmg of destruction spells +100%
Immolate inital dmg +25%
Fire spells +4% dmg
30% chance of becoming immune to shadow or fire for 4 sec if hit
Soul Leech - 30% chance of direct dmg spells returning 20% of the dmg caused as health
Shadowbolt and Incinerate gain +20% of total spell dmg bonus
Corruption (dot) gain +36% of total spell dmg bonus
Shadowfury - AE Shadow spell + stun for 2 sec....I am having visions of Shadowfury -> Hellfire -> Shadowfury -> Hellfire
edit:
Actually, forgot about Seed of Corruption spell (1044 shd dmg over 18 sec, then 1110-1290 shd. dmg AE to all mobs in 15 yards).
SoC -> Shadowfury -> Lifetap -> Hellfire
