There weren't a lot of SEO-related sessions at Google I/O, but affiliate programs often come up in the SEO equation, and Google did happen to have a session about automating the use of affiliate links to monetize your web site.
The session looks at the who (sites with promotional content), the why (control, flexibility, and conversion), and the how (leveraging the platform to scale requirements/site).
"Some of the most profitable web sites on the web use affiliate links to both drive traffic and monetize their existing traffic," says Google in the description. "This talk will walk you through how to automate most of your existing processes using the Google Affiliate Network, similar to how other larger websites do this today."
Here's what Google's Matt Cutts had to say about affiliate links and nofollow at the recent SMX Advanced conference.
Affiliate programs are of course discussed in Google's quality guidelines, which are the basis for the Penguin update. Here's more on that.