Since Guild Wars 2 came out, one of the most common criticisms has been that it lacks an endgame - to be more exact, that it lacks the standard MMO endgame, where everything you've been doing gets tossed out in favour of raids and the like. In response, the Guild Wars 2 team has put together a quick article about what they see players doing when they hit max level - and you should read it . Unless you're the git in China who tried to steal my account this morning. You may burn in Stygian Hell.
Put in simple form though, the Guild Wars 2 endgame is more about scaling up than changing the nature of the action - later zones moving from picking apples in an orchard to warfare situations, dungeons getting tougher and bosses more dangerous, and encouraging people to continue focusing on the bits of the world that interest them. If you like exploration, there'll be plenty of things you haven't found. If you like PvP, you can go and do that. If you like story, then at least the first 30 levels of it will be very different for every race and storyline combo. There's certainly no shortage of content.
Will this actually work? We'll see. Unlike other MMOs though, such as World of Warcraft and The Old Republic, ArenaNet isn't betting its future on endgame action. It needs to offer plenty for people to do, yes, but even if everyone who signed up for the levelling part of the game ups and quits, everyone still wins if they're drawn back for the expansion packs over the next few years.
That link once again: Guild Wars 2: The Endgame Reimagined