I just wanted to point out that this past month I hit 70 on both my Mage and my Hunter. I rule.
I've also been working on my Rogue quite a bit. I've gotten him from 35 to 45 in about 2 weeks.
I've also been playing my Priest, but that's a huge pain in the ass. I don't know how other people do it. I've got her up to 32, and it's taking forever. I originally had her specced Shadow, but I actually have her specced for Holy DPS now, shockingly enough. Shadow just didn't seem to gel for me. The Holy DPS spec I have right now is fairly effective, but the mana efficiency is atrocious.
I'm still working on my Paladin too, who's at 64 right now. She'll probably be the next to 70. I had respecced back to Prot for its AOE abilities, but I was having much more fun with Ret, so I switched back.
My Warlock has been sitting in Shattrath at 51 for months now, disenchanting and making potions. I'll probably pick her up again once I get my Pally to 70, and the first thing I'll do is respec back to Affliction. I wanted to try the Felguard, and I don't really care for it. Which is weird, because my Hunter is a BM.
My Warrior and my Druid are still sitting at 18 and 20. I have no interest in playing either. I don't like the Warrior class in general (at least not at 18) and I already have a rogue, warrior, mage, and priest, so I don't feel any desire to play my druid over the others.
I'm really looking forward to adding a Death Knight to my repertoire.