LOL, actually it was ME that said it gets converted to a SWF. What you do is look at slide properties and you will see that the background cannot be changed and it lists a SWF file. So based on that, I've always understood that the process of importing creates a SWF and configures it magickally to be the background.
When you said video, I was thinking perhaps we now are seeing a new playing field and maybe each slide would have a camcorder icon or the timeline with a red line through it.
So bottom line is that nothing changed in that respect.
Cheers... Rick