Wait, [warrior] tanks are speccing into blood craze now?
Honestly this is a degraded version of blood draining. Ok, come cata when healers will apparantly be mana conserving I can see a use for it.
The ONLY time this talent will be useful at 80 is if you are fortunate enough to have it proc at low health with no incomming heals for a second as overhealing pretty much renders this useless for the majority of the fight. It's 10% so even in ICC now that's 7-8k health over 5 sec or 1.6 a tick.
Looking at the scenerio now, burst threat tends to be the bigger issue especially in a tight dps fight, so it would seem like war accademy or cruelty would be the better option.