As you saw from the many posts yesterday the Google Developer Day was full of announcements and in-depth technical sessions. 63 videos from Google Dev Days around the world have been posted to YouTube. Jeff Huber’s US keynote (below) introduced the Mashup Editor (Radar post) and gave a concise overview of Gears (Radar post) and Mapplets (Radar post).
Other talks I heard good things about include: Mashups with the Mashup Editor, New Features in the Google Maps, KML Search and Dev. Maps Mashups, and Custom Search Engine.