For now, specifics are only available for paladin, druid and warrior tanks. The post hints that cooldown changes for druid and death knight tanks will be coming later, once developers can get a better handle on the complexities of the classes' abilities.
When asked for comment and analysis, Fox Van Allen's orc Grunk posited, "Me Grunk! Grunk fear change! Grunk smash!" Sadly, Grunk lacks the mental clarity to process the full meaning of all these forthcoming changes because as a warrior, Grunk does not stack intellect (and takes repeated physical blows to the head). If he did, the changes would be meaningless to him, as he'd have followed his dream and become an architect rather than becoming Orgrimmar's No. 3-ranked skull cleaver.
In lieu of expert testimony from Grunk, we have the full blue post just after the break.