Why didn't this come out of Adobe a year ago?
The Flash authoring environment is the best vector graphics editor I've used, even without the animation and scripting on top. They're still going to continue that, even if the Flash Player plugin is a bit behind.
Adobe actually made their Flash money from tooling and supporting services.
If they open sourced the spec and turned it into a commitie it would be in the same mess as HTML 5 and lose it's advantages (fast development, adoption for example).
If proprietary was such a big disadvantage why would it exist at all?