I am a resto druid levelling alone because I have a job and school and a life that prevents me from playing 18 hours a day 7 days a week, so I'm still level 73. However. Howling Fjord is probably more awesome than Borean Tundra; I just don't care about any of it. I just want to be 80. At that point, I can go back to logging in two nights a week without feeling bad about it.
In short, I hate the game for penalizing me because I'm not some unemployed nocturnal bum who can live for four days straight without sleep.
76 on my enhance shaman. Taking it slow though. I have a full level of rested and have been catching up all my other characters. It's nice to level in 2-3 hours on the lower guys as opposed to 8ish hours on the 70+ characters.