Async Conversations captured in WSDL Model

Hi Folks,
Is there a plan to inherently support description of async request response
communication primitives within WSDL.[i.e. rather than adding custom
extensions]
This is on the lines of the "partnerLinkType" extensions that are used by
BPEL Processes.If not, is there a demanding reason for the same ?

-Menon

--
Shift to the left, shift to the right!
Pop up, push down, byte, byte, byte!

-Ramkumar Menon
A typical Macroprocessor