I used a mod called "Omniscience" that did exactly that... I think NaturEnemy cast bars did that too?A while ago I used a mod that would specifically watch for and track the cool downs of other players.
Every time it saw an effect happen that had a known cool down it would pop up a bar with the characters name and time till cool down.
Haven't touched either since 3.0, so dunno if they're updated.
Mik's seems to feed off of the combat log, so I'd imagine it could show you anything that shows up in the combat log (and I don't think "Spell Ready!" shows up in the combat log)... I was mostly fiddling with it to get party DPS on my screen.
Suvega liked watching it yesterday -- since I'm working with Warlocks there was just a steady stream of red text for all the dot ticks.
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