Incremental recognition, Unobtrusive response

There are several multimodal virtual agents like MACH and SARA that provide
partial interpretation of what the user is saying or expressing facially
("incremental recognition") as well as backchannel 'listener actions'
("unobtrusive response") based on those interpretations. This style of
interaction is much more human-like than the strictly turn-based style of
Vxml (and related W3C specs) and of all chatbot platforms I'm aware of.

Is this interaction style (which might be called "IRUR") among the use
cases of any planned update to a W3C spec?

Cheers,
David