i got a questen. is this you raid spec or some hybrid farm/raid/pvp spec.
if its a pure raid spec than why have you skilled howl of terror and leave malediction out? 3% more damage
and for raiding affli dark pact is a must have if your oom and the healers have better things to do than healing your life tap dark pact is the most usefull spell you could get.
Felconcentration and imp felhunter some useless talents at pve. the felhunter regens more mana than he ever could use for his shadowbite. And if you use the immolateglyph than i woud rather prefer 1point in moltencore and 3points in cataclysm than the 5points in imp shadowbolt. In most situations you use shadowbolt max 2times to fill some time until you recast a dot or lifetapp darkpact... and the first sbolt have to crit to get a use for the second sbolt or haunt thats so a low dpsincrease that its not worth putting 5points in there.
i chose a 54/0/17 spec because i prefer the range talents and leave nightfall out (have the corr glyphe)
my specc
http://www.wowhead.com/?talent=IcxrbzbAoVqoIstZqzhVM
in my situation (the lock who always put coElements on the boss because of the spellpenetration even if there is a chicken or dk) so there is no use for me to take glyphe of agony or put some points there.
if a other warlock cast coe than i woud take the 2points out of imp.drainsoul and put it in coa.