Google Offers Online Payments

One of the neat things I love about Second Life is that the currency is transferable and exchangeable.  Unlike some systems where you can put money in but never get it out, Gaming Open Market has provided users an exchange house.  Now with Google Payment system I am interested if the Google will be the new currency benchmark for e-commerce.  Can they create a currency and back it up with their company value, setting an n exchange rate and offering it up in the currency market?  If so  will there soon be able to buy items with Yahoos, Googles, or Intels?  If the currency market were to crash how would that impact their own company?  So many questions and Slashdot offers so few answers!  Can't blame them though.