Session context token?

Jeff,

Kent Spaulding, the developer working on Sun's SPML2 implementation for 
the Interop, points out that our previous provider implementation 
returns an opaque token (in our case, a "sessionID") that represents the 
logical session (or perhaps session context).  If the requestor passes 
this token as part of subsequent requests, it saves a great deal of 
processing on the provider's side.  It may also assist with audit 
logging, which you've indicated you expect will become important.

I believe that this feature (i.e., an opaque and optional session 
context element returned by the provider and passed by the requestor as 
part of subsequent requests) may be important enough and general enough 
to recognize as part of the specification.  I'd like to know what other 
members and participants think.

Would you be willing to consider this issue?