Google I/O 2011 contained a lot of really valuable information the problem is digging it out of the huge number of videos that have been made available. To help with this problem here are the videos of the Android sessions roughly categorized.

If you are looking for information on the ADK and the Android Arduino connection it is in the Advanced topics group. There is also an interesting overview of Honeycomb in the General/Future group.

Core Android development

• Android Development Tools
• Android Protips: Advanced Topics for Expert Android App Developers
• Designing and Implementing Android UIs for Phones and Tablets

Android with other technologies

• Android + App Engine: A Developer's Dream Combination 
• Best Practices for Accessing Google APIs on Android 
• Building Android Apps for Google TV 

Advanced topics

• How to NFC 
• Taking Android to Work Android Open Accessory API and Development Kit (ADK)
• Leveraging Android Accessibility APIs To Create An Accessible Experience

Compatibility and porting

• Bringing C and C++ Games to Android
• Building Aggressively Compatible Android Games 
• HTML5 versus Android: Apps or Web for Mobile Development?

Commercial Concerns

• Android Market for Developers
• Don’t just build a mobile app. Build a business.
• Evading Pirates and Stopping Vampires using License Verification Library, In-App Billing, and App Engine

General Android and the Future

• Fireside Chat with the Android Team
• Honeycomb Highlights 

Look out for more guides to the Google I/O videos.