Sorry, that was too short.
My opinion on versions - once per SWF is enough, no need to do it on per class basis. (how other flash.* classes can live happily with only one version defined in the player?) That's enough information, because if you find yourself in a situation that some API you used had changed, then knowing the version of the entire library is just the same as knowing the version of a particular part of the library. That just won't add any new information. If you hope, that in the future framework will be reogranized in a way that it's major parts won't make arbitrary dependencies to it's other parts, then, probably, each part would deserve it's own version. As of today, that doesn't make much sense, as you will need to work with a particular version of the entire framework anyway.
