The Google Webmaster Central blog has announced the first release of the Webmaster Tools API:
From our discussions with webmasters, we've consistently heard requests to open Webmaster Tools for third-party integration. The Webmaster Tools team has taken this request to heart and I'm happy to announce that we're now releasing an API for Webmaster Tools.
A developer's guide is also available for anyone that wants to have a play around.
There's fairly limited data/functionality available at this stage, but it's one to watch IMO.