It was raised by Stefan Eissing in [1] that HTTP/2 (not surprisingly) encourages UA/clients to reuse established connections even for differents hostnames, provided they "resolve to the same IP address and wildcard certs or matching alternate names in the certificate to match".
This obviously is not compatible with our strict checking of the SNI against the Host header... And I also fail to see how this will help servers with different (configured) SSL parameters (like SSLProtocol, SSLVerify{Client,Depth}, SSLCA*, ...), some of which cannot be renegotiated "due to current limitations in OpenSSL" according to the comment in the corresponding mod_ssl code. What's the point of SNI if it can be used to select the correct vhost before the handshake (modulo the port...), but TLS must possibly be renegotiated later for subsequent requests?? Thoughts? [1] https://bz.apache.org/bugzilla/show_bug.cgi?id=58007#c9