Would be an idea to get some sort of list together. I'm open to correction and will keep this list edited for optimal moments, these are my thoughts at optimal moments of use.
Note that this is aimed from a warrior dps point of view so taking into account typical positions for warrior dps. such as Rohashs platform on heroic conclave which I would imagine no prot warrior would ever be on. Also I've no experience on Heroic Nef, Cho'gall, Al'Akir, Council or Sinestra so input on those would be cool.
Tier 11
Magmaw
Normal - Worth holding onto in case of an ignition/flame pillar error. Shouldn't need using.
Heroic - moments of the nuke phase / recovering from an add explosion
Omnotron
Normal - Magmatrons AoE
Heroic - When Magma's AoE and shadow conductor are at the same time.
Chimaeron
Normal - Feud survival / Survive an extra swing in last phase.
Heroic - Feud survival / Survive an extra swing in last phase / Boost raid survival time as dot ticks everyone close to death
Maloriak
Normal- Either red phase before a flame blast or during a troubled moment in the final phase.
Heroic- Same
Atramedes
Normal- May possibly help during a searing flame though sound is sound which is the main killer so probably not very useful here.
Heroic - Same
Nefarian
Normal - P2 crackles
Heroic - Phase 3 crackles
Halfus
Normal - Furious Roar
Heroic - Early on to assist tanks / Furious Roar / Shadow Nova recovery
Valiona+Theralion
Normal - P3 Blackouts
Heroic - Assuming your suiciding P3 blackouts, some other earlier blackouts.
Ascendant Council
Normal - Burn phase, dying seconds.
Heroic - Burn phase, dying seconds.
Cho'gall
Normal - Burn phase, dying seconds
Heroic - Shadow add AoE / Burn phase
Conclave of Wind
Normal - Nezir's storm?
Heroic - Rohash's shield, cooldowns fit around the 1st and 3rd occurrences.
Al'Akir
Normal - Burn phase.
Heroic - Burn phase.
Tier 12
Shannox
Normal - Little to no use for raidwide cooldowns here.
Heroic - As above
Beth'tilac
Normal - Used in conjunction with your healers and in a rotation with other raidwide cooldowns for the burn phase.
Heroic - As above
Rhyolith
Normal - Use just before a concussive stomp in the last phase when the raids health isnt topped up.
Heroic - As above
Alysrazor
Normal - Used in conjunction with your healers and in a rotation with other raidwide cooldowns for the burn phase.
Heroic - As above. Or if things get really funky during a firestorm.
Baleroc
Normal - Personal cooldown on a shard stack overdose or if called for to help another. Not majorly useful.
Heroic - As above.
Staghelm
Normal - Used in conjunction with your healers and in a rotation with other raidwide cooldowns for the scorpion phase.
Heroic - Best used during the orb phase to help ranged.
Ragnaros
Normal - Seed phase, as a reaction to impending sons failure.
Heroic - Phase 1: First Magma Trap
Phase 2: Second set of seeds
Phase 4: Either killing First meteor or running to new breadth after killing meteor.
Note: Use Rallying Cry with consideration and not on schedule. (unless your healers tell you otherwise) This public safety warning was brought to you by Iyona! ^.~