No, not as far as I can tell. The linked document has two options for opportunistic encryption, one of which is without server authentication, but that does not mean without certificates. The draft http://tools.ietf.org/html/draft-nottingham-http2-encryption... also states that the certificates would be used, just not necessarily checked.

My issue with the use of certificates is that it would in practice probably mean required manual server-side configuration, which would be a barrier to adoption (even if self-signed certificates are allowed). I would prefer a certificate-less approach that is available by default and for all sites.

The proposal also requires HTTP/2.0 for opportunistic encryption, even though we could probably make it work with HTTP/1.x too.

Well, ignored certs would be functionally near-equivalent to no certs.

If implmentations ended up keeping some meaning for them, you could look at how most ssh server keys are generated - no configuration.