So I've decided to write a review of Guild Wars 2! Some background on my perspective: I haven't played a ton of massively multiplayer online games. In World of Warcraft I made it all the way to level one. I played Lord of the Rings Online for a few months and enjoyed it, and the same for The Old Republic. Both turned grindy and I lost my interest.
Ok, so, GW2: it's awesome. Let me count the ways!
1. The graphics and visual content are gorgeous. Exploration is a blast, and there's always something new to see. The cities feel populated and live.
2. The dynamic events are fun. Sure, some are just "protect the caravan", but not all. Once I logged off in a friendly NPC fortress and when I logged back on it had been taken over by centaurs and burned to the ground. So we had to take it back over and rebuild it!
3. Character skills and abilities. I'm playing an elementalist and the mechanics are just plain fun. There are ability cooldowns, but they don't govern combat. It's hard to understand why without mentioning:
4. Mobile combat! Most abilities can be used on the run. You have to keep moving to dodge enemies and to get them into the hitboxes of your abilities. When an ability comes off cooldown you can't just use it unless you're in the right position. Combat isn't just a rotation of abilities in an "optimal" order because a lot of effort goes into positioning. Some enemies are fast, some are slow, and sometimes your movement abilities change based on your skills.
5. Instant travel. Once you have visited a place you can instantly travel back to it for a handful of copper. This means that there's a lot less running around, and all your foot travel is to new and exciting places, which leads to:
6. Exploration! The exploration system is excellent. You get rewards to visiting new places, killing a wide variety of creatures, seeing new vistas, and completing maps. The game deliberately rewards you for spreading your activities out. For example, monsters that have been alive for a long time give bonus experience points -- if you want to get the bonuses, you have to venture off the well-traveled routes.
7. Conditions and boons. These are the debuffs/buffs that are common in many games, but their mechanics are tweaked and more interesting in GW2. For example, elementalists can cause both bleeding and burning to do damage over time, but the effects stack differently. Bleeding stacks on intensity, which means that the more stacks of bleeding that you put on a target the more damage the target takes each second. Burning stacks on duration, which means that adding more burning doesn't increase the damage per second, but does lengthen the amount of time the target burns for. These distinctions make a huge difference when you're cooperating with other players to take down a boss. Which brings us to:
8. Ad hoc grouping! You get to work with whomever you're close to. You don't need to intentionally form a group to quest together, you can just go wherever you want and start walking next to whoever you want to team with. Rewards are automatically shared to everyone, so there's no competition between players and no reason to begrudge someone joining your group.
Those are my impressions after the first week of play. I plan to continue, so I may have more to say later on as I advance. I haven't tried much PvP or World-vs.-World play yet, but I plan to.