Rebecca Nesson made a point of importance (to me, because my son has Asperger's) -- and that is that Second Life is being used as a testing ground for people with Asperger's to practice social interaction without the pressure of face-to-face meetings. Here is a blog about this called Brigadoon.
Here are some other discussions about using Second Life for this purpose.
A second shot at life.
News.blog: 'Second Life' helps Asperger's
My question about this is that many of the problems with communication for people with Asperger's have with face-to-face interactions is about reading emotional queues on the faces of others, and learning how to interact with people in group settings. Second Life will not help with these problems.
Hmmm... not totally convinced about it's importance, but I'm open.