Many people are touting Public Quests as one of Warhammer Online's killer features. However, so far, I'm not very impressed with Public Quests.
A Public Quest is an area of the game in the open world which goes through a multi-stage fight. Everyone in the area can participate and work together to finish the battle. The first stages usually go through killing increasingly more difficult minions and the last stage is a boss. At the end, loot is distributed by a Random roll + Modifiers. You get a modifier based on how much you contributed to the fight.
The problem with Public Quests is that you need a minimum number of people. You also need a tank and healer. If you play at odd times, or stumble upon a PQ when no one is around, it's pretty much pointless. As well, the Empire and Dark Elves don't have a tank class, which makes PQs in their territory frustrating. Seriously, Witch Elves don't wear enough armour to tank a teddy bear. Perhaps this aspect will get better in later chapters.
Then, if you have too many people, the PQ devolves into a zerg, with everyone running around and spamming spells. There's no strategy or elegance. I don't really find that fun.
I think PQs will work nicely if you start with a good group. But starting with a proper group negates the entire "public" aspect of it, and it becomes just another dungeon fight.
Public Quests remind me of Alterac Valley (before the reinforcement timer) only without any PvP.* It's like a giant zerg. When you hit Drek'thar or Vannadar you hope to God that you have a half-way capable tank and some healers, and dps that doesn't react to getting aggro by running out of the room like a chicken with its head cut off. At least AV ensures that you have 20-40 people. Imagine showing up in AV with only 5 people, no tanks, and no healers. That's pretty much been my PQ experience.
*Let me preempt the wags: "So, just like normal AV, then?"
Finally, I hate the loot system. It's very annoying if you have a high contribution and roll low. If you have a low contribution and you roll high, it feels like you don't deserve the loot. If there are a lot of people in the PQ, only the first 10 or so will get a reward. This is a terrible design decision. Everyone should at least get the smallest loot bag. It's not your fault that a lot of other people decided to show up today. At least the loot bags offer you a nice choice of loot. You usually get to choose between an item for your class, some crafting components, or some gold.
It's a bit odd that I don't like the loot system, given that I don't mind rolling for loot in a normal dungeon. What really makes the difference for me is that PQs explicitly call out your contribution and give you modifiers to your roll. In a normal dungeon, there's a polite fiction that everyone in the group contributed equally, and so gets to roll on equal terms. It really sucks to be first or second on the contribution list, and yet end up with a white loot bag. Random + Modifier is more annoying than Random alone. Honestly, I'd probably prefer if the PQs didn't count your contribution, and just rolled equally for everyone in the group. Or even if everyone got the same loot bag, but the quality of the loot inside was randomly determined.
So those are my thoughts on Public Quests. It's an interesting idea, but being utterly dependent on other people showing up hurts. Also, Random + Modifier is a terrible loot system.