What is it about SL that interests Robert so much? The revenue model first of all distinguishes it from other virtual reality worlds. Users buy and sell services, objects and real life items like music and artwork. Land can also be purchased and built upon.
As a side note, each "island" of land in SL is a separate Linux server. The plots of land are auctioned off by SL to developers or real estate moguls, who then resell smaller plots of land to individual users. The currency used in SL (the linden) can be exchanged on an open currency exchange market for real world currency.
The ability to control the universe is in the hands of the participants. Linden Labs (the owners of Second Life) come up with tools, but users implement them by creating objects and even applications.
Designers, architects, musicians, programmers and other are making real money in SL - they are making full time wages working within this virtual worlds.
Robert points out that operating system are just a system that navigate to and store files. SL is the same. You can have word documents and real life documents within SL.
Patrick, Robert's son, was insightful about the future of SL - "Some people will work full time in the virtual world. Some people will never really get it."
