Nothing says it quite like the devs themselves: "ArenaNet's Eric Flannum and Colin Johanson are going to be chatting live on our Twitch TV channel in just about one hour. Join them as they explain how both single and multi-player RPGs have evolved and how GW2 showcases these changes. Then learn how they plan to tackle one of the genres most challenging aspects: The End Game."
If you have questions about this topic, feel free to tweet them to us @arenanet and we'll try to answer as many as we can at the end of the talk.
http://www.twitch.tv/guildwars2
Head to the link above in about thirty minutes to participate!