With the changes to Nightblade in 1.4, many players are coming into the NB fold from other specs. Since this spec was already on the ascendancy due to its burst cooldown and defenses, NB is definitely the most common spec to see a rogue in WFs at this point.
However, the new buffs to NB are weighed down by the nerf it received through the changes to Anathema. No more 75% reduction in healing. Since Anathema + Fell Blades was really required to kill healers most of the time, NB really lost its edge in a key area, although all-around it is still very strong.
With the predominance of the spec but the loss of surefire healer killing, I have decided to venture into the Marksman tree. MM is very powerful and while I rarely had Marksman rogues kill me as NB, it always felt vulnerable to them. And vulnerable it is. Here is my group PvP and NB-slaying spec I've embraced after various MM build tests:
While many MM like to go 38 + x and spend points in Ranger or Assassin, I feel the final 13 points in MM are just too good to make up anywhere else. Adding Retreat, Eradicate and Sniper Pedestal is well worth the additional points.
Key abilities: Swift Shot, Barbed Shot, Rapid Fire Shot, Empowered Shot, Deadeye Shot
#show Improved Hit and Run
cast Improved Hit and Run
cast Empowered Shot
use Words of War
#show Deadeye Shot
cast Deadeye Shot
cast Bull's Eye
Like Nightblade, Marksman is cooldown-dependent to a degree. However, the major MM cooldown, Improved Hit and Run has a shorter cooldown (86 seconds) and adds an incredible amount of damage, especially if you remember to put down Sniper Pedestal (naysayers be damned, its awesome).
MM is very powerful in group situations with its ability to assist melee and add huge amounts of damage, or pick off wounded targets without putting you at great risk. The biggest downside is that it is very squishy, so you need to rely on your speed and maneuverability to stay out of trouble. If you get pinned down, you're done.
This spec massacres Nightblades. Eradicate will remove nearly any cooldown they pop (Ebon Fury, Nightrage, Blackout, Twilight Shelter, etc.). Without Ebon Fury, a NB has no chance of killing you, as you can keep him at range all day. If needed, Cleanse Soul can get you out of a sticky situation, as 90% of NB damage is magic, but you really shouldn't need it. A NB can protect another buff for 6-9 seconds by popping Cleanse Soul or Twilight Transcendence himself, which makes him immune to eradicate, but this is fairly uncommon and with Getaway, you should be able to still get to range and remove his CD as soon as this ends. Plus, you just made him waste 3-4 cooldowns and not even survive.
I'm not giving up on Nightblade. I still love the soul and the play style. I am currently toying with a spec that abandons all reason and drops Infiltrator entirely, but its not ready for prime time yet (if ever). For now, I think the sustained damage of NB is not quite there, and its damage is too easily mitigated by kiting.
I still have Gunblade, but the current metagame makes killing Nightblades a priority and this spec does that just fine. There are a few Gunblade variants that are now more viable since the patch, including a MM-heavy Gunblade. I think the synergy between NB and MM still exists and that you can weight these 2 souls to your liking. I'll post a few of them soon.
Oh, and Deadeye crits for 2000 on 900 valor targets. Weee.