Be sure to check out A Second Life for Your Museum: 3D Multi-User Virtual Environments and Museums during the Thursday afternoon session.
Other Notes:
Awesome "wishlist" for museums in second life: http://e-artcasting.blogspot.com/2007/02/wish-list-for-art-museums-in-second_04.html
http://www.gslis.org/index.php?title=MI_Second_Life_Spurlock
http://www.museumblogging.com/2006/08/museums-and-second-life.html