I'll join in on this - we're looking at replacing GoToWebinar and the holy grail for us would be a solution that allows the playing of a video with audio over computers so that the participant computers see the video and hear the audio through their sound cards, not through their phone lines.

Seems that all the vendors I'm researching are hep on showing live video of people's faces (booooooooring) but don't address the idea of showing a short training video with audio passthrough.