Playing Sniper since launch and being one of those responsible for the original nerf to the class, I can tell you a buff will never happen.
PVE: The original Sniper Green Goo did up to 20% more DPS than all other classes when using the proper rotation on ops bosses. That was not the original intent of the developers, and they did not know this till after MM came out. So, optimized 16-man MM were 2 tanks, 3 heals, 1 marauder, 10 snipers. The healers were also doing off DPS because our ballistic shield could stack, and the tanks were taking very little damage. Imagine taking the boss down 10% in the first 4 seconds with 10 Orbital Strikes coming in. That came to 16 DPS (10 Snipers = 12 other classes) classes hitting the boss all the time instead of the intended 10. I really hate Star Pars (I play SWTOR to get away from the mods and addon's) and was very upset an operative I played with posted my numbers. The Nerf Bat hit hard when Rise of the Hutt Cartel came out and we have never been the same since.
PVP: The original Sniper/Gunslinger was built almost like a ranged tank. You took little damage and could control anyone that got close to you. Again very OP. The problem is they went too far in dropping our mitigation. The effect is today, we have problems in PVE because of them focusing on PVP. Playing PVE tank or Sniper I always notice the sniper taking more DMG than all the other classes. They forced too much natural defense to be optional and sacrifice our offensive capability. If you were to add more defense to your build you would be none viable in any of the specs for PVE end game. So, you learn to stand right next to the healer and yell at him you are dying because you are taking almost as much dmg as the tank.
Open World PVE/Heroics: Sniper/Gunslinger Marksman/Whatever is almost God mode today. I have no complaints there. I play all classes every week and Sniper are by far the most efficient time wise conquest class in game. I do conquest on up to 27 toons a week, so I know what I am talking about. As a Sniper, with the best, hardest hitting insta cast AOE in game I tear through group MOBS as if they are not even there. Three zones, heroic/CZ198/Ossus =100k Conquest in less than 45 min. Sniper/Gunslinger is my go too secondary class on all my tech classes for this reason. Heck I am leveling a Commando in Gunslinger spec just for the AOE.
Last: Sniper/Gunslinger is one of the tougher rotations and least forgiving to learn. If you do anything wrong, you basically must start your rotation over. Sit at a training dummy for a couple hours and learn the rotation. You will know when you screw up the rotation if you are properly geared (min/max) and are waiting on a cool down to come back up. You don’t need Star Pars (I refuse to ever use again). If you use the proper rotation, you will do mid-level (about 3rd class) high end DPS.
I love the Sniper/Gunslinger and wouldn't mind the days of old but understand why the nerfs did occur. I just wish they would not worry so much about PVP and think about the effect defensive changes has on PVE.