You will just have to dig on the farming builds and find out what works and what does not. You will see a lot of Rit/Mo and Ranger/Rits running a spirit spamming build for light to medium farming.
I played WoW this last summer for old times sake and nostalgia. The higher I got the less it was like the WoW of old. Glad that GW was still up and running. The biggest changes since you left are 7 heroes in your party; makes a huge difference. And Embark Beach is worth checking out.
As you know probably, GW 2 will be out "soon" like early next year probably. Unlike WoW, they are not destroying the old game to put out the new game. GW will still be here, whereas Vanilla WoW is just a distant memory.
You can get goodies in GW 2 from playing GW. No game changers, but veteran gear, veteran titles. Check out the Hall of Monuments in Eye of the North. Farming is not all there is to do. If you get 30/50 points in Hall of Monuments you will have all the goodies available to all your GW 2 characters.
http://hom.guildwars2.com/en/#page=welcome is the HOM calculator. The HOM itself is found in Eye of the North, which is in the Eye of the North expansion.
About nerfing. Some farm builds did get nerfed somewhat. But in general the new phrase is "power creep." With revisions to the Druid, 7 heroes in your party, a sturdier ranger pet since you were here I think; it is an improving GW. And now there are rumors of further good things to come including maybe even a Ranger rework somewhat like the changes to the Druid.
Oh, we forgot the War in Kryta and Winds of Change. Good quests there worth doing too. WoW has lots of competition these days, but GW still fits the gaming needs of many. I mean seriously, I have tried to find a better game but GW still has the most of what I want to spend my gaming time on.
Welcome back.