It appears bitcoin in the backbone to this economy just like the US dollar is the backbone for Bitcoin. So far, all other alt coins seem to be traded for bitcoins and (with the exception of litecoin) bitcoin is the ultimate medium of exchange. I predict Bitcoin is here to stay and litecoin will emerge as a medium of exchange but all the others have their work cut out for them to become more than a means by which to earn Botcoins and litecoins.