For the record, this has to be the definitive comment on whether virtual money is making the transition to real money.
I'm not the only one who's gone painfully through the process of asking whether virtual worlds are making the bridge to 'real' life.
CAN ELVISH GOLD PIECES EVER BECOME REAL MONEY? THE NUMISMATIC QUALITIES OF VIRTUAL CURRENCY UNDER THE LAW by JOSHUA DE LARIOS-HEIMAN, © 2005 (WORKING DRAFT) comes to the conclusion that under certain circumstances, under US law, virtual money 'should be imputed to be real money'.
Just wait till the money-laundering police come after Second Life.
We worry today about viruses jumping the species barrier (avian flu etc.) Will we one day worry about things jumping the barrier from the virtual to the real world?
I'm already thinking about it (not sure if "worry" is the right word... yet).