I'm really excited for this game, and there isn't a lot of information on the main site (guildwars2.com), so I'm gonna put some links up here that reveal a bit more. Of course, you could just look around the wiki yourself if you were so inclined.
http://wiki.guildwars2.com/wiki/Activities
http://wiki.guildwars2.com/wiki/Event_system
http://wiki.guildwars2.com/wiki/World
http://wiki.guildwars2.com/wiki/The_...t_of_the_World
http://wiki.guildwars2.com/wiki/Guild
http://wiki.guildwars2.com/wiki/Personal_storyline
http://wiki.guildwars2.com/wiki/Crafting