Cygnet, my worgen warlock on Whisperwind US, has done Blackrock Caverns, Throne of Tides, and Stonecore a few times now, and is working in Deepholm.  She’s going pretty fast toward 85 with a combination of questing and the dungeon finder.  I don’t plan on doing any heroics with her until I have the entire core set of basics down.  I’m still very intimidated by the idea of Deadmines and Shadowfang keep, as you’re just kind of thrown in and expected to know what’s going on at heroic difficulty.  And soon we’ll have Zul’Gurub and Zul’Aman back as heroic five-mans with the same pressure.  I do like that they’re adding some progression with 5-man content, though, so it’s not all about raiding.  ZG and ZA will only be accessible when you have gear from the other heroics, so it should be all good.