Evidence is the inclusion of Acquia's Drupal release in the Web Platform Installer of Microsoft IIS Web servers. Drupal is good software, Acquia is a good company, but Acquia Drupal is a .com, not a .org.commercial release,not a community edition.
NOTE: I misspoke in the original story, and it took two notes from friends to get this correction into my head. It's the community edition at Acquia.com, the free software, that is being offered, not the commercial release. Microsoft chose the community edition of Acquia over the community version of Drupal. My apologies.
Or take the new Silverlight, which also premiered at Mix. Microsoft had a French member of the Eclipse Foundation do a community port to the Macintosh platform. Open source becomes a tool toward achieving universality and ubiquity.
The positioning is clever. Now will open source developers buy it?