Tactical Mastery: every Warrior both loves and hates it. Loves it, because it makes stance dancing much easier (the talent lets you keep rage around while you switch between stances to use different abilities). Hates it, because most warriors consider it so necessary that even if they don't spec Arms, they have to use at least 10 points to level it all the way up. Recently, this little love/hate relationship has gained fire, because in the new Burning Crusade talents, Blizzard has moved Tactical Mastery over to the first tier of the protection tree. Warriors, as they are wont to do, smell blood in the water, and lots of them are fighting with Tseric to try and get Blizz to make it trainable instead, and remove it from the tree completely.
Now if my Shaman prediction hasn't convinced you of my greatness, it might interest you to know that I've leveled up not one but two warriors (and am working on a third). So I know what I'm talking about when I say: Blizzard will never take Tactical Mastery out of the talent tree. As Tseric says, learning how to stance dance and choose abilities by stance is one of the elemental parts of the class. Besides, Tactical Mastery isn't even completely necessary anyway-- one warrior in my guild never bothered to learn it, and instead counts on timed Bloodrages and DPS to make up the lost rage. So if you're waiting to TM to disappear from the tree, don't hold your breath.
Tseric has also posted an interesting "Design Philosophy for Warriors." Warriors, it seems, are like the workhorses of Azeroth-- every race can be one, and there are plenty to go around, so the class has to be as customizable and yet as viable as possible. The devs working on the Warrior class, Tseric says, aren't interested in removing tough choices-- they're interested in getting players to make them. Removing TM would do exactly the opposite. But at the same time, making those choices pays off-- as I learned yet again last night: dual wielding and duoing with a priest, my little gnome warrior was unstoppable.