I myself virtually ignored the development of the Guild Wars 2 until the very end of last year, when it was announced that the game was definitely seeing release in 2012 (In general I'm not a hype-follower of unfinished projects that have nothing to offer except fancy promises -- Hero's Journey taught me that lesson). Once I started researching the game, I found lots of things that sounded really neat but I still wasn't going to start get invested with too much excitement before trying it myself first. Since I haven't played a sub-MMO in nearly 2 years I didn't mind putting forth the full purchase price in order to get a spot in the announced Beta Weekend Events -- it's been long enough since I've bothered to seriously look at any AAA MMO that I felt it was worth the risk of disappointment.
I have to say, that once I got in and starting getting a feel for the game, I was sold. True, the public has only seen levels 1-20 so far and for all we know all the PvE content after that could be a a total fiasco, but it really feels as if the core mechanics of the game are solid and interesting enough that weaknesses in PvE content (if they exist) might not be enough to kill the game. If nothing else the PvP alone seems to be a big hit with the folks who like that sort of thing, which speaks for the soundness of the combat mechanics. And the Dynamic Events just -feel- seamless and organic and so much more fun than the staid cliche of text boxes, mob-tapping, spawn camping, and drop-farming that for some reason has never changed since MMORPGs were invented. And as a multitude of others have already said, the detail and love that has obviously gone into the art design, animations, and lore of the game is breathtaking in it's scope.
If you hate MMORPGs (or Themepark MMOs at all), you need to ask yourself what about them isn't fun for you, and then see if GW2 has changed that genre convention in their game. Because if you just hate being sent by people to wander the countryside on the behalf of NPCs and killing monsters for exp? Then you will be rolling your eyes at having to do these same things in GW2. Do you hate having to read lore or pay attention to quest dialogues? Then the Personal Story aspects of the game will fall flat for you. If you think 'playing dress-up with your character' is inane, you will not be interested in the main carrot of dungeons and crafting in GW2 (unique item skins). If you want full action FPS-style combat, then the hybrid model in GW2 with limited dodging and the ability to tab target will not scratch that itch. The game is also not a Sandbox; those who chafe at anything other than Total Roleplaying Freedom will not find that here, either.
BUT if you still love MMORPGs as a genre; if you're still into the whole 'explore a fantasy world and experience a story' thing and are just tired of stuff like static 'hotkey skill rotation while standing still' combat and gear treadmills and quest logs and mob-stealing and outleveling content and being unable to play with friends if they're the wrong level, wrong class, on the wrong server, or in the wrong faction, then there might be something for you in Guild Wars 2. But if you're burned out on the whole quest-based RPG thing and want to play a fantasy-themed Entirely New Type of Game? Then keep looking because such a thing has yet to be made and GW2 is not it.
Related Reading: [RPS] Wot I Think: Guild Wars 2