Google Drive SDK Early Access Program
Google has an SDK early access program setup for the Google Drive platform, and is inviting a select group of dedicated Google Drive developers to join the program. Giving them access to upcoming Google Drive SDK features and the opportunity to provide feedback.
Google isn't accepting everyone--they will be screening applicants based upon the type and quality of the application, number of users, and ability to implement and provide feedback on new features as they're made available.
An early access program seems like a good idea for API owners. It gives you the chance to test out your alpha and beta APIs, client libraries, SDK's with a controlled audience, before you release them out into the wild.
With the number of developers Google has, I don't think it will be a problem getting developers to sign up. But it seems like something you could even pay developers for, if you have a shortage of good developers in your API ecosystem.
An early access program fits right into earlier stories I've done on possible developer incentive ladders within API ecosystems.