Second Life is used for all sorts of things. Here's a video from YouTube that shows Decision Support World. I'm sorry, I just don't get it.
Digging around YouTube a bit, I stumbled across this video made by Dan Powers who created a virtual world in Second Life called Decision Support World. This is a virtual world that Dan set up to allow people to get together to model, collaborate, and share ideas about new projects.
The audio on the video is a little bad in places, and I'm not sure if it's completely clear about what he's trying to accomplish. I suppose if you're interested in virtual worlds that it's possible to use Second Life for such a thing.
It could just be me, but I don't see the usefulness of it. I'm not sure what you can do with such a thing that you couldn't do with just a conference call or NetMeeting. Maybe someone who's more used to or comfortable with virtual worlds would find it beneficial, but I sure don't get it.