ArenaNet just published a pair of Guild Wars 2 developer blog entries that focus on dungeons and underwater combat, and they complement each other nicely. They're both worth reading if you're looking forward to Guild Wars 2, but we'll give you the highlights.

Lore and Continuity Designer Jeff Grubb explains that dungeons are multiplayer, instanced adventuring areas that open up at level 35. There are currently eight dungeons in the game, and each one has a story version and three explorable versions. You'll have to complete the story version first to unlock the explorable versions. Bonus dynamic events can be triggered in the dungeons by player actions, by location, or even by random chance.

Game Designer Jonathan “Chaplan” Sharp goes in-depth into Guild Wars 2's underwater combat system, emphasizing that "there’s a huge amount of underwater content" to explore. When you dive underwater, you'll get a breathing appartus and special underwater weapons and skills. The transition from land to water is "seamless and immersive," and the underwater experience will be a "vital" part of the game. Expect to get your feet wet in dungeons!