Thanks to Thomas Bindl at Refined Labs for pointing out the launch of a new Adwords API - v2009. Seems they have created an entirely new API that offers some interesting new services.
* We've created new web services for managing campaign targeting options and campaign-level criteria.
* All web services share a consistent, data-centric interface with two operations: get and mutate.
* A secure authentication token replaces the login credentials required in v13 request headers.
The information about the new Google Adwords API can be found here.