I loved GW1 and logged over 5000 hours playing it. I like a lot about GW2 especially in certain aspects where they clearly improved over GW1 (persistent world, global trading post, jumping). However, there are many things I dislike about GW2 at this point, some of which GW1 seemed to do better at. As a result, unless certain things change in GW2, either by updates or coming expansions, I doubt I'll end up playing it for as long as I played GW1.
Do any activity for 5000 hours and you'll be disappointed with something else. I played a ton of Vanilla WoW and was disappointed with TBC (and it all went down hill from there). I played through Mass Effect several times and was disappointed with ME2 and ME3. The reality is the more invested you get, and the more emotionally attached you become, the harder it is to take something new at face value.
At the end of the day GW2 is what it is; assess it as a standalone game and play it if you enjoy it. The people desperately trying to compare it to GW1 will always be disappointed... and the people who don't consider GW1 to be all that good are more than happy with GW2.