So, in case people wonder what is happening, wrt to the timeline of the AV1 codec, here is some info.

This is final version of the bitstream and the specification of the codec. It will not change anymore (until AV1.1 or AV2).

There are not much features changes since the "release" that was announced before NAB (early April), but now everything should be clean and checked (checking that the spec actually matches the reference decoder, decoder model, profiles, ...), and a few bugfixes went in already.

Now, in a couple of weeks, you should have MP4 and MKV mappings finalized (yes, that means the files you've seen so far are invalid). And then it will be available to everyone (if you can encode it, of course).