As we announced on the App Inventor Announcement Forum, Google will end support for App Inventor and open source the code base at the end of this year. Additionally, in order to ensure the future success of App Inventor, Google has funded the establishment of aCenter for Mobile Learning at the MIT Media Lab, where MIT will be actively engaged in studying and extending App Inventor. This transition will happen at the end of 2011. At that time you will need to download your data from appinventorbeta.com in order to continue working with it in the open source instance of App Inventor. In the coming months we will send you detailed instructions on how to download your data.
Please visit the App Inventor user forums to get future updates on App Inventor.