In case you don't know about the twilight camps and bosses in silithus check this thread:
http://www.multiplayerstrategies.com/ms/index.cfm?page=topic&topicID=35077&categoryid=20&forumid=76

What I've been doing the past week is farming the twilight cultists in silithus up to the point where I can summon an abyssal duke. These dukes always drops an abyssal signet and 1-2 greens or blues. The blues are often quite valuable and sell for a median buyout around 80g with a max of 300g for "sword of zeal" in my case. Once you have 3 signets you can turn them in for a sack of spoils which also sometimes contain some valuable blues and has a chance of an epic sword worth alot. It's always BoE items so they can be sold at AH.
The twilight cultists also drop encrypted twilight text which at the moment can be sold for around 1g a piece due to the large amount of people wanting to gain reputation with cenarion circle.
You can't however kill the dukes alone, you'll need a group of 3-5 people depending on their skill and equipment. (Raid is an option). It is good etiquette that the summoner gets the signet and the rest of the loot is divided between the group members on a need/greed basis. However due to the AQ opening and new quests in Silithus most people are pleased if they can join for the rep gain. I've been spamming LFG whenever I needed a group and I've never been asked to share the loot. I know some people would rather be good m8s and share but that's not the case in my situation. (evil smilie)

All in all this entire deal nets me around 80g an hour by selling blues. If I didn't need the reputation myself I would sell the text and that would be about another 20g an hour so around 100g an hour + reputation with cenarion circle.
I believe this can be optimised if you buy the sets of AH and only care about the abyssal dukes. Haven't tested that yet though.