I just ran into this interesting site, with interesting statistics about open source applications usage. It is ofcourse based on participant but indeed looks relevant.
Open Source Application Statistics
Open Source Application Statistics
Mugshot and Fedora developers are working on ways to browse and find popular applications. Here are the current statistics for users sharing application usage with us. Read the full details
Site - http://mugshot.org/applications
Site - http://mugshot.org/applications
