This is big.

Google Set to Offer Payment Service to Compete With eBay’s PayPal
Google Inc. this year plans to offer an electronic-payment service that could help the Internet-search company diversify its revenue and may heighten competition with eBay Inc.’s PayPal unit, according to people familiar with the matter.
Read more at WSJ.com

It might backfire on Google’s face but if they find a proper way to encourage AdSense publishers and AdWord advertisers to use their new “banking service (by lowering the fees, for instance), that could really be a big business and huge revenue generator for Google. What they are becoming looks more and more like big companies used to be a hundred years ago: they would make us earn money, and keep the money for us in their bank. Next step should naturally be that we spend it on their products. Google to create a new eBay or a new Amazon? I doubt it, but something is to be expected towards this direction…