Most of my PvP experiences thus far have been pretty bad. There isn't any kind of honor system, so people who are 10+ levels higher than you are free to roam around and basically harvest you like wheat. However, there have been a few PvP encounters that were fun or too funny.
An example of the latter was when two enemies attacked me after I'd just finished off a creep. I usually don't have a chance against a good hunter, let alone a hunter and some kind of buddy, but it was worse in this scenario because I was ambushed by two hunters. The Dwarf hunter made the mistake of running out after me, so he became my primary target. I sacrificed my Voidwalker to give me a damage absorb sheild for a short while as I blasted and afflicted him. I got him down to a sliver of health before he used a potion, and I got him very low again before they killed me. Fortunately, being a warlock, I have soulstones, which allow me to ressurect on the spot instantly, once every half hour as long as I store my soul. I notice the injured dwarf and his night elf buddy weren't moving away, and the dwarf wasn't doing anything to heal. So, I ressurrected on the spot, blast the dwarf with a quick fire shot, and he went down. I was laughing so much I didn't care that I died again to the night elf, imagining the look on that guy's face when one second he was standing over a fallen enemy, and the next he had fallen with the enemy standing over him.