if theres a muti rogue, agi > WF. and since you mentioned enh sham, enh shams cant use wf themselves, therefore agi would benefit them too.

muti rogues exist even in guild that farms bt/hyjal. as they are very viable and at some cases stronger than even the revered combat dagger rogues in certain situations.

the only real requirement for mutilate rogue to operate is that the targets are poisonable, that clearly isnt an issue in TBC aside a few exceptions (lootreaver, the weapons in tk for examples)

sure, it is clear that enh shams are to buff melee dps, but they themselves does produce a significant ammount of dps too, even without them agi buffing themselves. doesnt hurt to buff them along while they are say buffing feral druids (OMGKITTYMEWMEW?) and mutilate rogues which uses agi totem more. hell, even combat daggers could does benefit from agi totems as WF proc has been constantly nerfed and its proc rate is very subjective at best. unlike warriors that hit damn hard for their white, rogues dont.

if you really want wf that bad, you can have the sham to refer what ray123 mentioned. and no, WF is clearly NOT always the air totem to be laid. agi is one of them, grounding is another (so long the raiding encounter allows, eg: maiden of pervert) and WOA totems (casters)

dont forget shams dont only buff melees in TBC, with heroism/bloodlust modding cast timers/channeling timers to a very horrendous ammount, adding up with WOA, you can turn a shitty as mage to a damn meter topper with just that 2 buff alone. (obviously its an exaggerated statement, but you get the idea. and yes, i clearly know you cant be perma bloodlusted/heroismed, but hey, if ur willing to do it, you can keep swapping shams once a sham is done doing it, for mega win rofl. although im not sure if its possible anymore as they disabled raid moving during combat some few patches ago IINM)