Layout Effects as Synchronization points

As a multimedia designer, I would like to see some reference to layout 
effects in the synchronization of the presentation.  For example, to play a 
sound during a transition ("Whoosh!"), to start on video as a slide-effect 
moves the video on-screen, or in completely audio terms, as a fade-in/out 
effect is stated/stopped. This dramatically empowers the capabilities of 
SMIL for creating good presentations, to the extent I'm surprised it wasn't 
even hinted at in the specs.

I think a stong part of this relates to the inclusion of scripting to 
create the simpler transitions (such as those described above).  At least a 
basic object-model could be defined to describe how a transition might be 
programmed.  It also questions the seperation of the layout from the 
temporal interaction.  Transitions inheretly cross these bounds.

Andrew n marshall
  student - artist - programmer
    http://www.media-electronica.com/anm-bin/anm
      "Everyone a mentor,  Everyone a pupil"