Annalee Newitz has written a fantastic article which gives interesting insight on the possibilities of the future of Second Life.  The article, titled "Your Second Life is Ready" explains her initial visit to Second Life and outlines some of the possibilities for the future:

"For example, a retailer like L.L. Bean could have a “door” to an SL store on its Web site, inviting people to jump from 2-D browsing into a 3-D saunter around, where an avatar with your exact mea­surements could try on clothes for you. Or a consumer-electronics company could offer in-person technical support from an avatar who had a precise 3-D replica of, say, that new digital camera you couldn’t figure out, and could show you which button you needed to push. As the wall between the Web and Second Life grows thinner, having an SL account might become as common as having an e-mail address."

I love Newitz's article because it makes the concept of Second Life so easy to understand, even for the least technologically savvy.