My main is a level 60 Paladin with full Lightforge Armor. When you roll a Paladin you have to remember one thing. Your a support class. This means your a jack of all trades, but master of none. You can heal, but no-where near as well as a preist. You can tank, but no-where near as well as a Warrior, and you can do DPS (Haha!) but nowhere near as well as a Rogue/Warrior/Mage.
What this means is that in end game raids you will be doing nothing but spamming your low mana heal (Flash of Light) during the boss fights. You will also but cleansing and buffing. That's it. You will not be doing any damamge. Personally i find this dull for 3-5 hours a raid takes...
In PvP, Paladins are pretty powerful, if you play them well and you have good gear.
To be a good Paladin PvP player you need to outlast your target. This means your battles are long, and boring or quick you result in your death.
My personaly opinion is that if you want to be a support class then roll a Druid or Shaman as they do everything better than a Paladin does. If not, pick a class that defines your style of play.
I liked my Paladin and there are still aspects I love about it (Self Heals and Cleanse while playing Solo). I have now rolled a Warrior though as I feel I suit being the Tank/Damage Dealer rather than the Support.