I hear lot of whining over the move of TM. Sure it is helpful for stance dancing but the fact remains that you don't need to do alot of stance dancing to be an effective warrior. and if you really need to switch stances a warrior can just wait till he has zero rage (which should happen often) in order to avoid wasting any.
Tactical Mastery in my opinion is a situational talent good for alot of situations. With it you can more easily overpower or revenge if your in the beserker stance, you can pop beserker rage if your in any other stance and you have more easy access to your other spell interrupting abilities.
It makes these abilites more accessible. They still cost the same amount of rage, they still have the same effects, they're just accessible. When looked at in this light it's a useful talent but not that "absolute neccesity" that people claim that it is.