I'd say the real answer is probably no on this one.

But I know the software that could do this well and it's free. It's called Wink. It's a screencapture animation program so if you can show the diagram on screen and zoom into it illustrator, you can capture it in wink at various stages, it will create the timeline for you. You can add audio or add your own popup labels to it.

Xara is awesome, but not for what you're wanting to do. Better to use a training tool for training demos.

http://debugmode.com/wink/