After Google discontinued its support of Android App Inventor on December 31st 2011, it has been taken up by Massachusetts Institute of Technology - Center for Mobile Learning, and will be re-launching its service in Q1 2012 for general public access.
Currently it is impossible to extract the source code from your former projects, does MIT plan to support this? Has there been any progress in doing this?
If you download your project and unzip it, you can see the source code: the list of components used, their properties, the blocks used, how they are connected, etc. That's probably not what you want, though.
If you're asking about seeing Java source code, that's not possible. App Inventor programs are never represented as Java code. See this question .