I myself played GW1 for a while but utterly disliked it...
Took me a while to eventually check out Guild Wars 2, because honestly the other games I play were getting boring.
So; started checking out some videos, some artwork and the occasional stuff and slowly but surely it became a bright point for me to cure boredom.
After participating in... two Betas and a stress test (Eventually) I can not say it is a perfect game... but it sure does feel good to play, it looks nice and the character design is quite well done. (Could still be better but that's not the point)
The environment of the world is just amazing; exploring trough snowy mountains towards tundras and the likes just feels amazing.
In all fairness, the hype started with indeed more known blogs and vlogs... but perhaps also by how it was presented to the world.
The second part which created the snowball effect; is the entire new system, because almost EVERY MMO out there uses the "standard" it does work, but for pure DPS or Heal classes it's quite dull and constantly the same.
The entire new way skills work in GW2 could eventually set a new standard.