Google Checkout was released today. In the great slashdot tradition, the story is sold as "Google is releasing an X killer" where X is a product that does something similar but has a totally different goal. (Google Spreadsheets the "excel" killer, etc).
Two things about Google checkout are very interesting to me. First, the ability for Google to provide the user with some sort of confidence in the checkout process. I never really liked Froogle all that much because it'd point you at some random store that just happened to have a website.
The second thing I like is that Checkout offers an anonymous email service. The ability to shut off email from a seller if they get out of hand is very, very nice. (as I understand it, it also offers the ability to forward email for the inevitable email address change. However, it seems the main functionality is being anonymous).
Of course, there's always a down side to things. I'm quite sure this will cause an increase in phishing emails for Google accounts. With that said, it looks like Google is using smart measures to make sure a stolen password won't be of much use. Also, I'd think that gmail users would be especially safe from phishing (when GMail team gets a phishing report, I'd assume they can retroactively filter it).
The checkout support site also has some (basic) information on what the anti-fraud team does. I can assure you, the process is much more complex than that site makes it sound :-).