Auto-Attack is a large amount of your DPS. The Det nurf is huge... Unless..
Due to this re-balance, I'm curious if the value of Determination on gear will be increased as well to compensate? putting it on par with SS/CritRate in terms of amount allotted per ilvl?
The Crit Buff is very likely to make Bard/Machenist extra powerful too, so that's another interesting aspect. Bard keeps 2 DOT's up 100% of the time, and relies on heavy crit chance already.

As for tanking, I think this buff heavily places warrior into the high DPS tank spot, it makes me curious what Dark Knight actually gains from it's stances.