So I hear that google is making a 3d chat room that's free and embeddable in web pages. Sounds pretty cool, but I've always preferred text myself. Also it's not for linux right now, so I can't use it on my typical OS.
The problem with trying to get a 3d environment for chatting is that it uses a lot of resources and many people enjoy chatting while doing other things. If you aren't paying full attention to the environment then you don't get much benefit from the 3dness. I'm sure that google will do a good job with it (as usual), but I'll wait until it's more mature to say whether it looks like something I would want to use or not. In any case I think having a full 3d environment just for chat is a bit of overkill, it seems like I should be doing something (like killing monsters) if I'm going to pull out the 3d.