Why would anyone want to explore something like Second Life? Let's narrow that... Why would a librarian want to visit Second Life? One more time... Why would I want to visit Second Life? I think the human/computer interface is fascinating. IRL (in real life), I find people's reactions to new technologies... well, fascinating. Some very bright and gifted people react with absolute horror when faced with different technology applications. Other people literally embrace it. I think the gap will be smaller with the next generations; interfacing with a computer will be second nature.
So back to Second Life. During my visit to the library, I explored some files-- as in drawers in cabinets containing paper. Many of these were teaching guides on humanities and science projects. It was a familiar experience-- as familiar as pulling open a file drawer at my physical desk (a little neater, perhaps). I would think this would provide a level of comfort for many people. So, this virtual reality isn't on the level of the simulator in Crichton's novel, Disclosure. The immediacy isn't there, of course.
I can easily imagine a virtual library, with virtual librarians and other patrons, all browsing for information, having conversations, and sharing an experience, all from the comfort of your home, or airport, or wherever. Or maybe I just read too much sci fi.
Visit Second Life... for the very best reason: it's just plain challenging and fun.