Before I go any further, I should set down some credentials.
I've been playing WoW for a couple of years. My first serious toon was a hunter called Saund. The guild I'm in is mostly social and I have been with them since about level 5. The guild were short healers (gee, now there is a unique story :) ) and so I rolled a pally to help the guild. I like healing, and I mostly ret just for soloing. I leveled Saunder 77 levels the hard way. As holy. (The last three I just couldn't wait and powerlevelled as ret to 80). I still firmly believe and feel very strongly that unless you have played the class before, there is no better way to become good at your class unless you level in the spec you plan to be in the end game.
Yes, I know all the pros for leveling specs, and doesn't dual specs help, but in the end it doesn't matter what role you are in an instance you need to know your class. The better you know your class the better you are likely to be.
I also have another 80 pally, Saundin. I carted him across to Shadow Council so that I could help an old Uni mate Kasias and his guild.
I also have terminal altaholism. All up I have 24 toons over 5 servers, of which 23 are Alliance but I really dont play more than Saunder, Saundin and my Drood, Furryferal. I try to make my altoholism recognisable so most of my toons are Saund*. It's just easier. Those three are *more* than enough to keep me busy.
I have 37 days playtime on Saunder, 39 on Saund, 17 on Saundin and 4 on Furry. I have cleared Naxx and ObS once each, which certainly doesn't put me in the elite category. But I enjoy it and hope that I can bring some insights to the blogosphere.