I had a post earlier in the thread that got cut off so let me post the entire thing:
Let me outline some things here.
So people are worried about progression and not having anything to do? When people think of progression they're typically conditioned to think about gear based progression (vertical advancement) of ever increasing stats. Right around, at, or after the level cap you will have obtained the very highest stat based gear you can find and you think well that's it right? Wrong. Like GW1 you don't just obtain a single piece of gear that is one size fits all, you're going to need to obtain gear sets and upgrade components for said gear sets for every single possible scenario that you might come across. You wouldn't use components that had +5% to giant slaying if you were killing demons now would you? Besides the statistical gear you're going to obtain, you'll also likely want to obtain gear that looks awesome because we all know deep down that's why people obtain gear. No one looks at someone and says “OMFG THIS GUY HAS +200 strength!” No, they look at the gear and think “Wow, he looks awesome, I wonder where he got that!?” How awesome gear looks goes hand in hand with where you obtained it and what it took to obtain it.
Next you have Traits that you're going to obtain for your class. Currently Traits are undergoing a bit of a redesign, but here's what we do know about how they're acquired. If you didn't know Traits are one way to differentiate one player of one class from another. They're meant to be used to compliment your builds. You'll be able to slot them in the different Trait lines and change them out at anytime out of combat for free. So as I said Traits are going under a bit of a redesign but as far as acquiring them we do know that you'll have to traverse the world to obtain them and each class obtains them in different ways. A Warrior might train, eat, and battle to obtain theirs, Necromancers might take the hearts from their enemies, Elementalists might seek arcane tomes, etc. So you're going to want to acquire all of these if you want to be as effective as possible.
Like GW1 it's very likely that GW2 will use Titles & Achievements as another way of progressing your character. In GW1 there were Title tracks where as you increased the levels of these tracks you obtained ever increasing ranks of these titles. When you turned on a certain title, it would then buff you with stat increases for killing certain enemy types and the like. Some of these Titles were and still are stupidly difficult to obtain in GW1 and that will carry over to GW2.
Player skill – Even if you obtain absolutely every single possible statistical upgrade for every single scenario, you will always be able to improve yourself as a player. This is literally a never ending form of progression. With a dynamic combat system that makes you entirely self reliant, cross profession combos, AI that isn't just sticking to one guy and uses many different variables to determine who to kill, dynamic events making content unpredictable, and a focus on actual team play, you're not going to ever be “the best” unless you actually strive for it. No gear will make you a god in this game.
Going Beyond -
Content will never become obsolete due to a patch or expansion, all content will be relevant and this is a good thing. The dynamic event system, scaling, and sidekicking system make sure of this. Why would you ever want to have less things to do as a game ages, it makes no sense. I could go into this a lot more, but it's besides the point at hand.
Anyways the point is ArenaNet is making a game that is fun to play, you get to choose what you do, when you want to do it, and who you want to play with without a monthly fee holding you hostage. There's nothing gating your from doing content in the game, only your ability as a player and ability to work with others. Some of us have been playing the same type of MMO for far too long and we're plenty happy to get away from the gear treadmill that gets erased every few months, we want a game that is based on pure skill like nearly every other genre in gaming and above all is actually fun to play just to be playing it, not because we feel obligated to do so otherwise our money goes down the drain.