It looks vaguely cool, somehow game-like.
Is it 'teacher friendly'? Can you control the attention of the class in a virtual situation.
Could be used for for discussions, immersive learning, problem based learning, various forms of experimental and experiential learning.
Links-
http://www.slideshare.net/olga.caprotti/mathematics-education-in-second-life/
http://blogs.ala.org/yalsa.php?c=1&more=1&pb=1&tb=1&title=second_life_best_practices_in_education
On the other hand check out this article.
