One thing that came up in the discussion was that Adobe wouldn't open source due to proprietary internal content.
However I replied this may or may not be true - Adobe has open-sourced several large projects. Flex (http://www.adobe.com/products/flex.html), for example is a big software product that Adobe switched to open source in 2007.
From an article back then:
"Ward outlined the transition as having the following steps:
Today - Creation of Mailing List for Discussion
Summer 2007 - Public Bug Database and Daily Builds
Second Half 2007 - Flex 3 Released
December 2007 - Read Only SVN Access, Patches Welcome
2008 - Committers with Write Access, Creation of Possible Subprojects "
Why would Adobe make Fireworks open source when they plan to continue selling and updating the last version?
"While we are not planning further feature development for Fireworks, we will continue to sell Fireworks CS6 as well as make it available as part of the Creative Cloud. We will provide security updates as necessary and may provide bug fixes. We plan to update Fireworks to support the next major releases of both Mac OS X and Windows."