The MMO side of it is fairly meaningless to me at present, my interaction with other player characters has been minimal as I'm still in the early character levels. I can, however, say that the game itself has enthralled me. The backstory is detailed and interesting and the quests are excellent so far. Unlike Morrowind, I've found that I can jump into the game and see lots of things, make a fair amount of progress and still have lots more to do - Morrowind always felt empty to me.
When I've levelled up enough, I'm really looking forward to playing some mutli-person quests and instances - this is where I think the game will really shine, with each person having to take a specific role within the game and perform it well to keep the team working. I've never experienced this yet, so when I do I hope it'll be pleasurable. I'm on the RP PvP servers, so human interaction will start being more frequent when I move out of the safety zones - if only because I'll get my n00b ass owned on ;)
What strikes me now more than ever is that the people who jump onto GDNet wanting to make a MMORPG have really got their work cut out for them. I'm not talking about getting the network system, the graphics systems, the person interaction - I imagine that's just fairly 'normal' game stuff to do. What they haven't thought out is the content. With World of Warcraft, Blizzard have got stacks and stacks of the stuff. Content, polish and style oozes out of the entire game - it's this which I think the wannabe MMORPG coders take for granted. It's the same with many other games though, but with the MMORPG games you want people to stay around for a while. And for that, you're gonna need content to keep them there.