IMPORTANT: I am a Marauder player, not a Sentinel player. I'll do my best to state the Sentinel version of whatever I am naming, but if I miss something, don't Gibbs slap me for it.
To be honest, I am rather content with Sent/Mara in general. That doesn't do much for me or anyone else on the thread however, so I'll post some minor adjustment ideas.
There are some incredible Annihilation PvP players. Sadly, the fact is that a really good enemy healer can shut down one via dot cleansing. A spec like Vigilance Guardian / Vengeance Juggernaut has dots as well, but they don't rely upon them half as much as Annihilation does. The ability to cleanse dots, however, is a part of the game, and I don't see the game as a whole benefiting at all from having an already-effective dps class use uncleansable dots. As for the acidblade-type ability (permanent buff until used, then applies dot) idea proposed by other members of the discussion, I feel like class mechanic uniformity partially destroys the unique feel of each class. I think Marauder/Sentinel should keep its unique dot system as it is. I'm not 100% behind this idea, but perhaps it'd make sense to lower the cooldown on Deadly Saber so that the dots do not have to be built up every time, they continue at three stacks if used on cooldown, but fall off it a player fails to reactivate them.
PS: I am in favor of changing the 6 stacks of juyo form to 3 (and thus doubling the effect of each stack) to effectively reduce the 'get-going' time of Annihilation without messing with any damage values or other abilities.
Carnage PvP: I don't see too much need for change with this spec. It requires skill to use, yet is effective if used correctly. In the wrong hands, it suffices as cannon fodder, which is also appreciated. Just a minor suggestion, perhaps the Ravage/Master Strike root effect could be made more effective by giving the attacker temporary immunity to stuns and knockbacks. Just a thought, if you don't like the idea that's chill with me. I'm not a very big Carnage PvPer (or really, Marauder PvPer at all).
Rage - Smashmonkey PvP: I'm perfectly content where it is. Powerful as an aoe spec should be, not overly strong (though clearly on the edge).
Annihilation PvE: I see no reason for this spec to change. Fun, fluid, effective.
Carnage PvE: The spec is good, as is obvious by the crazy number people hit with it. However, the RNG on the opener is rediculous
. The problem is that you really can't change that without redesigning half the spec, or more than that. To be honest I think the cheif issue lies with the Gore/VT (??? / Dispatch) proc. It's nearly impossible to know whether to use Gore or not, because while you may not have a Ravage -> Force Scream rotation lined up, you might get the proc the next second, and thus completely wasted a free Gore. There has to be a better way to handle that.
Rage PvE: I don't really see much reason for this spec to change either. I don't really think it was ever designed for single-target ops bosses, so I don't see a reason to change it to such.
Just my two cents. You can disagree (and you probably will) but remember we're all here to make the class more balanced.