Zangarmarsh's a pretty cool zone, honestly. However, so far the quests I've done in it are all over the place. There's like 3-4 different named mob quests, and honestly I don't like it as much as Hellfire Peninsula so far for questing (plus, this may just be my mediocre LCD monitor, but it's a lot darker to me than Hellfire Peninsula). I think it's because the quests in Hellfire at least start out interesting, while Zangarmarsh starts out boringly, with crap to kill naga or random mobs. It does have a couple neutral factions, though, one of which actually starts out at Unfriendly like it's Timbermaw Furbolgs.
Also, I did the lower level wing of Coilfang Reservoir (the Slave Pens) and it's a bit buggy, but I think if they fix that then it could be a good instance. It's way longer than either wing of Hellfire Citadel (which means it takes about 2 hours) and IMO not as interesting, but it drops better loot. And similar to getting Thrallmar/Honor Hold rep from Hellfire Ramparts up to honored, with the Slave Pens I was getting Cenarion Expedition rep. If you don't like Naga then the instance will get old fast, though, cause that's 90% of the mobs. The other 10% are some Outland version of the Makrura guys (crab people). I did it with an unconventional group, with a druid as the tank (did perfectly the whole time, so thankfully druids can compare to warriors, at least in 5/10 mans) and an enhancement shaman, BM hunter (great dps and awesome group buffs out of that spec, it's underrated), a priest, and then myself (respecced to affliction for this fight).
I can't find a good warlock spec to be honest. Affliction is going to get nerfed, I just know it is, considering I walk into a camp, drop 3 dots on every mob, and walk out alive from drain life for 230ish and the 3-4 siphon life procs for 120ish healing with fel armor. I may just go back to the felguard because it's still easy, but less overpowered, and requires me actually paying attention. I really wish I could go destruction, but god does it blow. Soul Leech/Nether Protection both suck, Backlash is good, Shadowfury is mildly useful but nothing special, and IMO at least they're going to have to give t4 and t5 bonuses specifically for destruction to make it worth getting. However, that may change when I get incinerate, and I do plan on respeccing whenever I get it just so I can see if its dps goes way up. Again, just IMO but incinerate >>>> shadowbolt if you go heavy destruction. I also have yet to try any of the world pvp stuff, but Zangarmarsh is where the rewards really seem to kick up, outside of getting exalted with Thrallmar (+150 spell damage +21 spell crit rating sword ftw).
Oh, and goldwise I feel like I'm insanely rich, but I know I haven't played nearly as much as most of the catasses in the beta. I'm only at 233g but I also play at most about 2-3 hours a day, maybe longer if I'm not dealing with something else.