Google Web Fonts was launched on May 5, 2010, today on September 27, Google announced that they have built the "Google Web Fonts Developer API," which provides a list of fonts offered via Google Web Fonts.
"Results can be sorted by alpha, date added, popularity, number of styles available, and trending (which is a measure of fonts growing rapidly in usage)."
"We've received lots of requests from developers for a dynamic feed of the most recent web fonts offered via Google Web Fonts. Such a feed would ensure that you can incorporate Google Web Fonts into applications and menus dynamically, without the need to hardcode any URLs. The benefits of this approach are clear. As Google Web Fonts continues to add fonts, these fonts can become immediately available within your applications and sites," Google stated.
Google says that "some developers have already helped us test this new API over the last few months, and the results are already public." Adding, "take a look at TypeDNA's photoshop plugin as well as Faviconist, an app that makes generating favicons as simple as can be, and Google Web Fonts Families, a list of Google Web Fonts that have more than one style."
Check out the Google Web Fonts Developer API documentation to get started.