From Googles website
At Google, we want to help developers build better web applications. That’s why we have created APIs and tools to quickly enhance those applications, integrate with Google products and reach millions of users.
That is also why we are holding Google Developer Day.
Google Developer Day is a chance for programmers around the world to meet Googles developer product teams and learn something new be it an introduction to GData or a deep dive into KML. Its also an opportunity for us to listen to you and hear about what youre doing today, what you would like to do in the future and how we can help make that happen.
Whether you are writing an AJAX application with the Google Web Toolkit, integrating Google services through GData or using Google Maps to create geo applications, we hope you will leave Google Developer Day with a new set of building blocks to use in your next project.