Theorycraft-like addon for tanking?

Is there an addon which (checks your gear and talents or maybe not, but) shows something like "how much less will be an average hit on you with +1 more defence" or "with +100 more armor" or "with +1% more block".
It'd be like Theorycraft, which shows how much more will the ability hit with the next +10 str, +1% hit etc., but for tanking

TankPoints. Shows total damage mitigation (statistical) among other things.

Thanks a lot, really nice addon!

Are you using it? The only thing that I think is buggy is... Am I right that it doesn't take your strength into account, which should increase the amount of your block (btw, I don't know the exact formula for it) and thus total reduction?

tankPoints = maxHealth / (mobDps * (1 - totalReduction)) is a simple but very cool formula, leaves no further questions.