This isn't breaking news by any means, but hopefully some may find it helpful.
Adobe CC 2015 Removes Prior Versions by Default
Before you click the Update button to install the new CC 2015 version of your Adobe application, consider whether you want to keep the prior version installed first. By default the new Creative Cloud installer will remove prior versions.
To keep your prior version installed, click "Update" and then select "Advanced Options" to expand the window. De-select "Remove old versions", then click "Update" to start the process.
For more information check out this Adobe blog post.