All silences -- gone. They unbalance PVP since there is no equivalent to "silence" melee players. Also, the different types of silences are unbalanced.
Some CC measures have to remain because they're integral to the class. Warlock fears and Mage frosts and slows, for example. Rogue poisons and saps are in that category and can't really be removed without completely changing the character of the class. Hunter freeze traps and such would stay. Hunter silence, sleep and disorient shots would be gone. Warrior intimidating shout, also gone.
The tradition of PVP here at WOW has been that lightly armored caster classes have to stay away from the more heavily armored melee players to keep alive. But over the years some melee classes have been given mobility skills which make that extremely difficult. It SHOULD be difficult for caster classes to maintain distance, but not extremely so. There needs to be a balance between casters who need range and melee who need to get close. Remember, a melee player doesn't take long to dispose of a caster class once they close the distance.
That being the case, rogue shadow step: gone. Warrior heroic leaps and charges: gone. DK death grip has to stay because it's an integral part of the class, but chains of ice: gone (in pvp). If you're a melee player you don't get to bounce around like that unless it's a skill on a long cooldown.
Naturally there has to be some tinkering with classes that lose these stuns and silences so as to not make them weak. The ultimate goal is that any class should be able, all things being equal in terms of skill and gear, to engage in a fairly even fight with any other class. There should neither be OP classes, like the warriors are now, nor UP (underpowered) classes like the balance druids.