this is a good one, but not everything we know is writtenTry to be as well informed as possible. Read the blogposts and FAQ on guildwars2.com and the stickies on this forum.
don't forget youtube, as there are a lot of interviews about this game out yet
a few examples:
Izzy Gamescom 2011
Panel Comic-Con 2011
PAX Prime 2011
Balancing and combat systems Izzy
PvP and Guilds
Endgame & guild customization
Lore Panel
and much much more.