I don't think there ever will be a MMO like WoW again.
Not that there won't be MMOs, but they don't tend to have the same combat that we're used to, and not necessarily the same mechanics. Also - that was 10+ years ago at this point, ultimately if you played it back then chances are you have a lot less time now.
I've tried various MMOs since WoW but there was always something missing.
I still to this day think that Guild Wars 2 could have been a WoW beater but for a lot of people (myself included) I just couldn't get on with no tanks, healers and DPS situation. I didn't like the way that it worked in that game. Outside of that I loved the graphics style, the jumping puzzles, the maps, the F2P aspect.
Then there's FF14 - as a Final Fantasy Fan I always loved jumping into that, the music on the menu is almost enough to get me hooked. And while there are tanks, healers and DPS the combat just feels so slow, mostly because it's not as quick as WoW.
And that's where I think a lot of problems lie - there's many MMOs out there, but realistically what a lot of people are looking for is a WoW clone to some extent with updated graphics.