We have four options, as I see it. No host header, incomplete URL's in the protocol. I believe this solution is unacceptable to all concerned who understand the problem at all. The current situation is operationally critical at large web sites, and addresses need to be conserved in the Internet until V6 transition actually happens. Protocol not crufted up and complicated forever.
Simplicity is next to godliness.
Solutions to these problems involve one RTT, as a 1.1 client would have to handle an error, and retry using 1.0 syntax. Extra packets are exchanged during transition to 1.1 to handle this error condition. Client implementations are more complex, and performance poorer during transition. This is clearly what the protocol should have been from the beginning. Transition to requiring full URL in 1.2, after 1.0 servers have been replaced.