I think a general consensus for this particular proposal was reached.
The disadvantage with Pragma: Keep-connection is that it can't be used 
with downlevel proxies because current proxy definitions pass along 
pragmas thus if a proxy doesn't support the pragma but both endpoints 
do, there's some poor interaction.  In this respect, I tend to prefer 
Alex Hoffman's SESSION method proposal.  It has the advantage you can 
send multiple requests at a time and the server serializes the 
responses.  In addition it works better across proxies and is more in 
line with HTTPng.  The disadvantage of the SESSION proposal is it 
requires more server and client mods, but I'm willing to live with that.
Alex, can you give a pointer to the current proposal?
John