Glitch (http://glitch.com/) is a new MMOG that is still in the alpha stage, but looks like it could be right up my street. It's a new project by the team who started Flickr. The basic premise is that 11 giants are imagining this world, and the players are just tiny figments of their imagination. There is a fascinating interview with the guy who's creating it (Stewart Butterfield) on Gamasutra. There's also a player-created wiki.
I think the interview is interesting because he has the same problems with Second Life and There.com as I do - what do you do when you're in there? At the same time, he doesn't like the way that in games like World of Warcraft you don't leave a lasting impression on the world - i.e. you kill something but you can go on the same raid to kill the same boss tomorrow. Glitch is an effort to create a world that is changed and responds to the players, and I think it's quite exciting.
I managed to get an alpha account, and had my first go playing last Thursday (the game is only periodically open at the moment). The focus is on building things and learning skills, but unlike other sandbox style games (e.g. Wurm) there are also quests, so there's an entry point. The quests are silly too. I had one where I had to use my emotional bear (after equipping it with lips) to kiss 5 other players, after eating garlic. So the quests show you how the equipment can be used, and encourage interaction - I had to chat to the people I was kissing, I really couldn't bring myself to just run up, kiss them and run away!
There are going to be multiple ways to group players from that interview, so not simply guilds/clans/villages. Some are going to be 'religious' cults, dedicated to one of the giants. He also mentions corporations. It will be really interesting to see what forms, and if there are any differences in character between the two types of groups.
I'm looking forward to seeing this one grow, and really pleased to be on board at the alpha stage.