I can\'t start new projects anymore. This is what I do...
I've just had the same issue on Mac 10.9.1. For what appears to be no reason, when creating a new android project, the "src" directory is empty, and there's no activity_main.xml. I tried Werner's fix, but the URL had issues trying to download the files. Deleted Eclipse, and re-installed. This appears to have fixed the issue.
Actually - still having this issue, even after re-installing Eclipse...