Slashdot has a discussion page up about an interview with Will Harvey , the founder of There.
I haven't played There and don't intend to, even more so after reading the article. It is an interesting read though, none the less.
Second Life gets a brief mention -
CD When you released There, I think some confusion may have arisen because two other similar games came out at about the same time: Second Life [Linden Lab] and The Sims Online [Electronic Arts]. How did you approach that problem?
WH All three games have virtually identical press announcements as platforms for online socializing, or not too far from that. But if you look at the products, they are extremely different. Sims is a game, driven by game objectives, and it's actually not a very good platform for online socializing. It's not all that easy to have a conversation. It's great as a game, but that's different from the objective of There.
Second Life is an environment where people can build things. It's technically demanding. It's a different market from There's market, which is people who want to hang out with their friends. Some of them want to build stuff that will be interesting to other people, but the appeal of There is to people who want to socialize, not specifically to people who want to build things.