I tried splitting a .wim on to multiple cds yesterday. It worked. I would say flawlessly with one exception. Don't forget to number your cd's while you are burning them Other than that, it worked well.
I still have not found a link to the WDS demonstration video.
I'm not sure about WDS support. I think I remember seeing a video on their site about how to connect WDS. Hopefully someone from the SmartDploy support can chime in on that. I can't find the link.
I checked the latest release notes and it looks like the latest update for enterprise might support splitting a .wim. I'm assuming that is what they mean by "spanned media".
Here are the release notes. http://www.smartdeploy.com/Products/Downloads.aspx
I'm going to try it out today. I'll post back and let you know how it goes. If I could span that stuff on CD's it would be freaking awesome.