Really can't see the point... what makes libraries in a virtual world better/more interesting/sexier that reality. And if it is better than reality is that because it is all an illusion? One's imagination always IS better/more interesting/sexier.
I think my personality is much more grounded in interactions with real people. I know it is a useful levelling space for people with disabilities or maybe those who find real life social interaction difficult for a variety of reasons. That's great for them but I'm not sure Second Life is a place I want to spend my professional, or personal, time.