Eric Musco posted an update on the official forums regarding Sentinels and Marauders for PvP:
Update on Sentinel and Marauder | 04.06.2015, 03:00 PM
I know that some of you have been waiting for a status update on Maras/Sents, especially for PvP. Here is some info from the Combat team.
We would like to take this opportunity to discuss Marauders/Sentinels and their present state in the game. To do so, we wish to start by outlining the rotational design philosophies of the three Marauder/Sentinel rotations.
Carnage/Combat: Low Rotation Difficulty, Moderate Burst and Moderate Sustained Damage
Annihilation/Watchman: High Rotation Difficulty, High Sustained and Low Burst Damage
Fury/Concentration: Moderate Rotation Difficulty, High Burst and Low Sustained Damage
Marauder/Sentinel PvP Viability:
As it presently stands, Carnage/Combat and Annihilation/Watchman are performing well in Solo Ranked and Group Ranked PvP, respectively. We target a 50% win rate for each Discipline in PvP, and Carnage/Combat and Annihilation/Watchman are slightly above this ideal win rate. Carnage/Combat is the seventh most effective Discipline (out of 24 Imperial/Republic total Disciplines) with a win rate that is right on target. Annihilation/Watchman is ranked seventh in Solo Ranked PvP (out of 24 Imperial/Republic total Disciplines) with a win rate that is equally on target. Additionally, Carnage/Combat is currently in one of the top 5 Group Ranked PvP class compositions, and this composition has an 82.6% win rate. While win rates are not the sole variable that we balance PvP performance from, these numbers provide evidence of Carnage/Combat and Annihilation/Watchman viability in broad PvP scenarios.
Fury/Concentration is in the lower half of the PvP spectrum. Like other classes that are underperforming, this is, and shall continue to be, addressed in upcoming class balance updates.
While we plan to adjust Marauders/Sentinels in future updates, we do not expect to see any Marauder/Sentinel Disciplines receiving significant damage output increases. Each of the Disciplines is presently performing at our desired DPS markers, and we plan to focus on Utility in the future. Specifically, mobility and self-healing improvements are currently being tested. We’ll keep you up to date on changes in the coming weeks.
It should be noted that PvP success is continually changing as updates reach live and the community learns new strategies with their classes.
Looking forward, we will continue to incrementally improve the status of Marauder/Sentinel Disciplines that are not performing to satisfaction. This is the perspective that we hold for all Disciplines across all classes.
We will continue to collect constructive feedback from the threads, concerning all classes, and apply improvements through our continual class balancing updates.
-The SWTOR Combat Team