The rumored Gbuy (click to see historical tracking of coverage) has been launched under "Google Checkout" at http://checkout.google.com. It basically has the same exact interface from the sellers or buyer accounts perspective as when I first tested it in March.
As Chris Sherman wrote;
Checkout isn't a person-to-person, stored-value system like PayPal. But with its pricing and ease of use, it's a compelling alternative for businesses of any size that are currently using PayPal as a payment processing system—particularly with its aggressive pricing and incentives for AdWords advertisers to use the system.
If you are a seller, you can learn more about it at http://checkout.google.com/sell. As a seller, and an AdWords advertiser, you get a special little shopping cart logo near your AdWords ad in Google. (WOW). Here is the sellers demo.
Are you a developer and want to code in Google Checkout, check out Google Checkout API.