The University of Miami in the US has got together with the University of Dundee in Scotland to work with IBM on a project to develop open source software designed specifically to address the needs of older people, and help them to adapt to and remain productive in the 21st century workplace.
While I can certainly see that workforces in many developed countries are aging, and at the same time the pool of available younger workers is often shrinking fast, I am not convinced that the answer to lost skills and knowledge as this older workforce retires sits with software, open source or not.
http://www.daniweb.com/blogs/entry1828.html