Although this is a great place to learn/gather information, every bit of info should be interpreted and adapted to your char, your play style, your raid setup and your healers/dps'rs play style.
Avoid taking everything literally and terminal. A good example of this is the hit cap debate.
(I don't mean to sound condescending, its just a reminder).
I would like to gather more info on Piercing Howl though.
For me (my style and raid) I find Blood Craze and Cruelty very close to useless (not completely.. but very close).
So for me to consider getting Piercing Howl, it means a 6 talent point cost.
With those 6 talent points I can get instead Safeguard and Impending victory as well as 2nd point in Hold the Line.
So, my question is, how useful is Piercing Howl? how many situations are there for it to be useful? Of those, how many are for the role of MT?
And is it worth all of the alternatives you can use those 6 points in (not just the one I mentioned)?
In raid it will rarely get used as a competent dps with a slowing ability (hunter for example) will be used to slow mobs that are not suppose to reach their target or risk a instant kill. However in 5 man instances it is useful in Throne of Tides and Halls of Origination or any other fight where the tank will be kiting adds while the dps focus is elsewhere. So I suggest dumping it once you reach raiding and spend the point elsewhere.