Enemy Cooldown Tracking (with a twist)

[ibcurly]

I am looking for an addon that notifies me when my target has certain spells on cooldown at the same time.

Example:
Targeted rogue has ALL the following spells on cooldown: (cloak, shadow step, blind, vanish)
--Displays countdown of least cooldown left.
--Once ONE of the tracked spells is off cooldown, it displays nothing.

I'm basically trying to create the following notification:
"You have --this-- length of time to free cast your target because your target has all --these-- spells on cooldown"

Is there an addon that can do this?
Can WeakAuras handle this?

if not, isn't this a great idea for an addon?