The guy you probably read about was powerleveling with help from his guild, left out lengthy quests, didn't do any boss fights / events / escorting missions etc. and he played during all the beta phases so they could set up a plan how to do it the fastest way. He also started three days early (pre-purchased). Crafting gives loads of XP, he did that alot (and his guild gave all the crafting materials to him otherwise he wouldn't be able to do it).
I played for 45 hours and was around lvl 32 I think, there are 80 lvls and since you played GW1 you know that the last lvl is not the end of the game - not at all. It start, basically
The world and especially the cities are huge, especially compared to GW1.
Also this isn't really unusual, people do it with most (every?) online game and most of them are "finished" within days. But again, being lvl 80 doesn't mean anything at all. You could still be in the first city and reach lvl 80 through crafting if you wanted. The level scaling also makes the game challenging no matter where you are and what level you have - your stats will be reduced to that of a lvl 15 guy for example if it's a lvl 1-15 area. So exploring the whole world including the starting regions of the other races isn't boring and you still get XP from events and quests, still die if you don't watch out etc.