This is a somewhat blunt way to put it, but it has to do with "you weren't paying attention to the Adobe Open Screen announcement on May 1st." SWF, FLV, and AMF were all freed then and, apart from developers already working with Flash, it didn't seem to make great waves because of the sudden, low-hype nature of the announcement. A lot of the comments that day - here and elsewhere - were confused, cynical remarks along the lines of "I'll believe it when I see it," when they had _already_ put everything up.
The direction of Flash has been towards greater openness since around the time Adobe acquired Macromedia in 2005: One year later they released a new major version(9) with a new VM and a completely refactored API, and along with that they released an open source Flex 2 compiler.
Adobe would probably open source their own player and ensure it becomes the "de-facto standard implementation," if it were not licensing-encumbered.