I found that video and uploadet it on YouTube. It's pretty bad quality, but it seems to be running the DS Phat firmware on the DSi. How's that possible? Could this mean that older flash carts work on DSi then, too?
EDIT: YouTube linking didn't work, here: http://www.youtube.com/watch?v=auVVbmZiSKs
EDIT: YouTube linking didn't work, here: http://www.youtube.com/watch?v=auVVbmZiSKs