Yes, I know, this was released two weeks back, but I'm just getting caught up on some post backlog.
After seeing innovation after innovation built on top of Google Maps (the latest being the Seattle Busmonster), I really wondered why they haven't offered an official API. Well, now they do (noticed first via Vasanth).
From the website:
One interesting note in there: Google retains the right to put advertising on the map in the future. It will be interesting to see what they plan on doing with this. Will Google Adsense support location-specific advertising in the future?