well there is the option in a warlock/shadowpriest group to link the spells quite effectively altho the synergy relies primarily on the buffs to shadow damage it can pack quite a hefty punch

combine Shadowbolt (x2) with Mindflay.. making sure they are both bound to the same button (add macro to the SP that makes sure Mindflay is not recast half way through.. [nochanneling] or something as a condition)
then:
Immolate and vampiric touch as one (1.5 sec cast, both last 15 secs)
Curse of Agony and SW;P as one (one of the warlocks with curse of shadows for overall party buffing) (instant, both with 24 sec timer, SP talented)
Corruption with Vampiric embrace (instant - such a low mana cost on VE it doesn't matter if it is recast, watch out for the 10 second CD tho)
then SW;Death with either Shadowburn or Conflagrate
with a little practice you can pump out some insane dps, not to mention the fact that your entire group gets healed nicely with one or two shadowpriests in it and with Blackout as a priest talent you can guarantee that 1 in 5 casts will stun your opponent for 3 seconds..
2SP 3 warlocks seems like a good dps group.. there is less micromanagement then in a 1SP 4 warlock due to not having to use of life tap.. and your will be able to go on for much much longer as you will gain alot of mana from two SPs..

as for a whole team with a warrior.. it is a lot harder. shaman will still provide a huge dps boost in the form of WF, agility, str totems, but you wont be buffing his AP as Elemental.. and controling 2 or more melee is just not viable for most encounters, so options such as feral droods are a nono..
Edit: as Boylston Pointed out a resto drood or shammy is a good option druid for hots, shammy for Earthshield (threat) and dps buffs.
fury warrior +3 ele shammies + resto shammy would add the threat buff to your warrior (if you decide to go fury) an added bonus is that your resto shammy will have an added 9% crit to his heals.. (replace resto shammy with a holy paladin for more buffs and group saving divine intervention.. pally will benefit from 9% crit to healing spells extremely well too, also adds mana regen and threat reduction to your team)

4 shaman 1 balance druid is doable but can be difficult to time if you want specific spell rotations that include all of them hitting the same target at the same time (starfire+LB... :S)

fury warrior with ele shamans and hunter can be something along the lines you were looking for.. hunter can buff a little little bit.. will gain from agil and his pet form agil and str, and does some nice dps too.. might again be dificult to time.. as for max dps you realy need to be focusing on the hunters bow swing timer.

1pally + 4 ele shamans (the standard PvE instance team) 12% spell hit/crit is imba.. WF, agility, str totems for pally, healing stream and mana stream benefit the pally too.. pally buffs on the shamans. Mass AoE threat, all res minimal micromanagement (totems) make this the easiest and also the most effective team to manage/dps with.

I've been thinking about using a fury warrior as a clone before.. not as the character I control.. think of him as a slightly slower version of a felguard pet :P use the charge ability to get to the right range and let him go crazy :P not sure how well that would work tho.