I don't know if this works, still, but there is a way of making a macro that sort of does what you're looking for. There's no way to actually make a "smart" macro that searches for which ability is off of CD and uses that one, but there is (or was, again not sure if it's still working) a way of sort of fudging it. I was able to dig up the Ret version:
Code:
#showtooltip Crusader Strike
/startattack
/castsequence reset=0 0,0,0,Judgment
/castsequence reset=0 0,0,Crusader Strike
/castsequence reset=0 0,Exorcism
/castsequence reset=0 Hammer of Wrath
I thought I remembered a Prot version being posted on MMO-C at some point, but I wasn't able to find it. Maybe someone else knows some forum search tricks and can find it. This is the base, though, and you could build a Prot version off of it, I'm sure. I think you just want to put the highest priority ability at the bottom and go up from there.