No and yes (at least for those whose positions are predefined).
Spdy/3 has already sailed, but there will be a spdy/4.
Sorry addition to address Pattrick's response:
Maybe I am missing something but wouldn't all spdy specific headers be mandatory to come before an http protocol headers?Right now the only spdy specific ones are for the request line/status line.I would think other spdy specific headers (if there are every any) would be beneficial to come before http. This is one protocol encapsulating another, so it makes sense for the protocol encapsulating the other to need information pertinent to it before information about the protocol it is carrying.
All of this is actually not important as right now any other ':' header would either cause an error or be discarded (spec is not clear).
I think the core difference in thinking is whether spdy is being made to as efficiently carry HTTP as possible or be a flexible protocol that can expand over time and carry other types of data.