Currently, versions of Flash are in CFM format, but need to be in Mach-O format in order to work with the latest series of Gecko based browsers. This bug tracks the progress of that.
SPAM: New Components
*** Bug 282810 has been marked as a duplicate of this bug. ***
The Flash Player now supports NPRuntime, which works in Mach-O browsers, so I think this bug should be marked fixed (or whichever status is appropriate for fixed non-Mozilla software).