Talent exclusivity is nothing new in WoW, of course. We're used to 31 (and before that, 41, and before that 31) point talents that we can only get one of. But the original talent system was built with a lot more synergy in mind - it was expected and possible for people to choose talents based entirely on other talents they had and how those talents would work together.
Text vs. subtext
The new talent system still has that in a vertical sense - you can take Bloodbath (in the level 90 tier) based on your having taken Bladestorm, or Totemic Restoration entirely because you took Stone Bulwark Totem. But the change to exclusive talents at every tier makes for a system where each individual talent choice has a more definitive quality. You have Roiling Blood, so you don't have Unholy Blight. You took Asphyxiate, so you can't have Death's Advance. The increased role of exclusivity in the current talent system is my favorite aspect of it.
Furthermore, unlike in Cataclysm the exclusivity is not rooted in your talent spec - it is in face entirely divorced from it. The old system's exclusive choices were rooted in your being forced to spend points in a specific tree, a codified limit that was implicit in previous expansions. You could spend your talents how you liked before, you could be an arms warrior without the 31 or 41 point talent Mortal Strike, but you were doing it wrong and Cataclysm just made the subtext text. But now, talents are not specialization defined, which means you can choose Execution Sentence as protection or holy or retribution. I find the idea of talent exclusivity being purely based on the tiers of talents, and not what spec you are or how many points you spent in X to be a good move forward and a useful tool in helping players feel like their choices are important to their characters. If you can do everything there's no real choices to be made. You just do everything.
Static vs dynamic equilibrium
Now, some of the changes this causes are ones that take adjustment. Having Mind Control as a talent means that you may not actually take it, which means not every priest can Mind Control in a pinch. Exclusivity of this kind isn't necessarily bad, but when it comes to abilities that players have grown accustomed to having, like the aforementioned Mind Control or Enraged Regeneration, then it can sting to suddenly have to choose between the old familiar ability or no-brainer talent and a new shiny you want. Frankly, it's what I can end up lacking in this system that compels me. Taking Avatar, for instance, gives me another DPS cooldown but at the cost of the power of Storm Bolt, an excellent pulling technique that adds great damage against bosses.
This shift in how exclusivity works makes every talent decision serve the dual purpose of defining what you can do, and also what you can't do. It comes down to the talents themselves, now, to be compelling or not. Design no longer requires certain talents to be weak because other talents would make them too strong - each talent must stand on its own. Whether or not we see clear favorites in the coming weeks will tell us which talents need a redesign, and this can be seen divorced from synergies that much have skewed the results. That's worth supporting, in my eyes.
It's open warfare between Alliance and Horde in Mists of Pandaria, World of Warcraft's next expansion. Jump into five new levels with new talents and class mechanics, try the new monk class, and create a pandaren character to ally with either Horde or Alliance. Look for expansion basics in our Mists FAQ, or dig into our spring press event coverage for more details!