"With the Google Analytics Data Export API, you can develop client applications that download Analytics data in the form of Google Data API feeds. Your client application can use the Data Export API to request data from an existing Analytics profile for an authorized user, and refine the results of the request using query parameters. Currently, the Data Export API supports read-only access to your Google Analytics data."
The API is useful to create different interfaces for Google Analytics and to process the data in interesting ways. For example, you might build a notifier that alerts you when your site has a large number of visitors or you could use the data to display a list of popular posts from your blog.
There are already some interesting applications that use the API, including a dashboard that integrates data from Google Analytics, a SEO tool that analyzes the keywords used to find the site, a mobile interface for Google Analytics and an AIR application.
"The Data Export API is easy to use and provides read-only access to all your Analytics data. Any data that's available through the standard Analytics web interface is available through the API. The Analytics API is a Google Data API. This is the same API protocol for Google Calendar, Finance and Webmaster Tools," mentions the Analytics blog.
If you don't think this news is very exciting, you should become a trusted tester for Google Analytics to try other cool features before they're publicly available. "Current Trusted Testers have recently tried out such features as: Event Tracking, Data Sharing, and Outbound Links."